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Jared12319
03-22-2018, 09:49 PM
Hey all! I'll try to write this as concisely as possible, since there is a lot of information. First off, I love my S5, and have owned it for a little over two years. I've had basically no problems with it until I hit about 89,000 miles, then the following happened.


I was planning to move across multiple states (driving the car there), and started noticing one day that upon heavy acceleration, my car didn't feel normal. I felt stutter after 4K RPM's and was getting a flashing CEL that would sometimes stay solid. I immediately took the car to an autozone to get it quick scanned with an OBDII scanner. The verdict; Cylinder 6 misfire

My initial thought was to swap coils 5 and 6 to see if the problem followed a potentially bad coil, but they had the right coil in stock so I just bought one with the intention of swapping to OEM if it was in fact a coil problem.

Swapped the old coil with the new one, and the problem stayed.

Put my old coil back in, but swapped 5 & 6. This time the misfire jumped to cylinder 1 (wtf?)

Swapped coils 1 and 5, and cylinder 6 misfire came up again.

Had a broken vacuum hose on the line that runs down bank 1 to the air box and front of the engine. Fixed it, but the problem stayed.

I then replaced all of my spark plugs (NGK platinum), and the problem stayed.

After that, I swapped all coils with new OEM ones, and again, the problem stayed.

I then started reading about it possibly being a battery issue, and on a certain corvette forum (along with one thread on an Audi forum talking about an older A6), a person had virtually identical problems and ended up solving them with a new battery (the theory was something along the lines of voltage not being high enough for the fuel system upon heavy acceleration). Anyway, I tested my battery and it read SUPER low. Like 11.9-12v after sitting for a couple hours. Perfect, I thought. Swapped battery's and the problem went away for a day, but ultimately came back. Put my old battery back in since after testing it outside the car, it was at 12.7V. Oddly enough, it would immediately drop to 12.4 when hooked up. Did a parasitic draw test and couldn't find anything (although I believe I could have used a better method)

Started suspecting clogged injectors, so I put gum out through the system and crossed my fingers. Problem stayed.

Got frustrated dealing with it myself so I had the car diagnosed at a reputable euro shop in town, and they came up with the following; recommended changing all injectors, doing carbon cleaning, replacing PCV (diagnosed positive crankcase pressure), and going from there. They weren't 100% sure what the problem was, but that's where they said I should start. At $3,500 for the job, I wasn't to take a gamble on it possibly not fixing the problem, so I opted out. They also smoke tested the system and couldn't find any vacuum leaks, as well as checked compression on all cylinders (everything was fine).

Still thinking it was possibly an electrical problem, I started checking all of my fuses including the under-hood fuse box (Couldn't find a diagram if my life depended on it). Didn't find anything abnormal, so I plugged the ECU back in and gave up.

The next day I was driving and noticed it had no problems; regardless of how hard I was accelerating. I ran the car extremely hard for about an hour and couldn't get it to misfire. At this point I had no scanner, so I went back to the shop and they were nice enough to ride around with me and read live misfire counts to see if it was actually working right. Same thing, it wouldn't misfire AT ALL.


Not knowing what I had done to fix it, I packed everything up and was on my way to a new state. Before leaving I picked up a generic scanner just in case. Halfway through trip I got a CEL: System too lean bank two

Had no idea what it could've been so I kept driving. During the drive I would also get ESP + Parking break malfunction lights coming on randomly. I thought maybe it was just all of the snow packing against the sensors, because it would sometimes go off after being on a clear road.

Anyhow, for about a month I drove and ignored these codes whenever they came up (I know, stupid). I would still get system too lean bank two; along with the ESP and parking brake malfunction light.


The time came recently where I wanted to sell my car, but knew I couldn't with the codes popping up all the time. So I started by replacing the PCV valve.

The system too lean bank 2 code stayed, and the other codes popped back up after a day. At this point, I finally bought a VAG401 tool to diagnose

Swapped battery AGAIN just to verify it wasn't that; problem stayed.

Tested short term fuel trims;

Bank 1; mostly fine, sometimes lean under load.
Bank 2; started as being fine at idle, but lean under load. Then switched to rich at idle, rich under load, then back to Lean no matter what.

When I thought things couldn't get worse, the car started running super rough. It would misfire sporadically; random misfire code and cylinder 8 misfire. Sometimes it would misfire 50 times in a matter of seconds at idle, not misfire at all under load, and then not misfire at idle just an hour later.

Tried Techron injector cleaner just to see ; nothing.


Then, the car started misfiring on 5,6, and 7 (not 8); but would only throw codes for 5 & 7


Read upstream o2 sensor voltage;

B1S1 Voltage; hovered at 1.48-1.5V no matter what
B2S1; Voltage hovered between 1.48-4.5V


Starting thinking that may be the problem, but it didn't make any sense to me since to my knowledge, high o2 sensor voltage indicates running rich, but I was running super lean.

Around this time, I got a MAF code under load with ESP and parking break malfunction while on the freeway. Tested MAF; values were in range under idle, and under WOT in second gear.

Ran with the possibility that o2 sensors were my problem; so I went to swap B1S1 and B2S1 to see if the super lean condition and higher voltage would follow the sensor from bank 2.

Accidentally Broke connector when putting sensor from bank 2 into bank one (wire twisted around my o2 sensor socket and I didn't even realize it).


Since it was broken, I Bench tested it with a propane torch for voltage output; couldn't get value to go up at all. Tried multiple hook up methods.

Also made a smoke tester, and re-tested for vacuum leaks; couldn't find any.

Swapped the o2 sensor back to bank 1, and got a brand new sensor for bank 2. After that I read various measuring blocks and noticed a few things,

- Even with the brand new o2 sensor, the sensor voltage was reading from 1.45V to 5V. Wtf?
- Fuel trims looked good at idle and under heavy load for the most part, but under slight acceleration bank 1 goes about +13, and bank 2 goes up to +27


I really don't know what to do at this point. Although it hasn't thrown codes again since replacing the o2 sensor, I know there's still a problem because of the fuel trims, and Cyl 8 is misfiring here and there (mostly at idle, but single digit numbers. Not like before where it misfired like crazy at idle and under load). Here are my considerations at this point;


- Maybe it's my LPFP (no codes)
- Fuel filter? (no codes, and doesn't make sense to me since it's only really lean on 1 side)
- Bad or clogged injectors (However; No codes, lean condition only on bank 2, misfires only on bank 2)
- HPFP (no codes)
- MAF (Maybe I ran a bad diagnostic?. But again, it's only really lean in bank 2).
- Bad relay
- Bad ground wire? Car was rear ended about 8-9 months prior to the problems and had $20,000 worth of repairs done (mostly in the rear. Only a bumper in the front because I tapped the person ahead of me).
- Bad ECU?
- Carbon buildup


Any help is hugely appreciated. Ideally I want to fix the problem for as cheap as possible, since I'll already be taking a huge loss when I sell the car. My next step was going to be pulling the intake manifold and checking/cleaning my injectors, carbon cleaning, and going from there. Unless of course there's a better or more likely solution.

Sazexa
03-23-2018, 02:03 PM
Has it ever been carbon cleaned before?

new2s5
03-23-2018, 02:23 PM
What he ^^^ said.

plat
03-23-2018, 02:29 PM
+1. My first suspect is carbon build-up. At 89,000 miles, if you have not had the intake valves cleaned, carbon build-up might be causing these headaches.

brilliant_black
03-23-2018, 05:51 PM
Literally 9/10 times any sort of misfire on the V8 S5 is due to carbon buildup.

Since they have to rip off the manifold to clean the ports you might as well change all the fuel injectors too.

Also check motor mounts. At that mileage I'd replace them with the 034 motorsport ones.

Sent from my SM-N950U using Tapatalk

Jared12319
03-23-2018, 08:23 PM
Literally 9/10 times any sort of misfire on the V8 S5 is due to carbon buildup.

Since they have to rip off the manifold to clean the ports you might as well change all the fuel injectors too.

Also check motor mounts. At that mileage I'd replace them with the 034 motorsport ones.

Sent from my SM-N950U using Tapatalk


Interesting, I wouldn't think carbon would be the first, second, or even fifth thing to consider. But I'll begin the process of seeing how I want to do the carbon cleaning. Since I'm getting rid of the car, I likely won't do motor mounts.

What would explain the other problems I'm having? High o2 sensor voltage, etc.

jaypilot75
03-24-2018, 08:12 AM
My initial thought is the ECU is on its way out. Given your description of faults, several are unrelated and interdependent except in the ECU. I do remember reading some time back about ECU issues in earlier S5's. Then again, you said the car was rear ended. The parking brake control module is in rr quarter panel?? And the battery regulator module under the spare . Check comm b/t those modules and CAN comm as well. Im know some batt regulator modules are intergrated and some independent particular to specific models.
Also, If you didnt clear the preexisting dtc's , the ecu will ( or may)still try to compensate for them. Try clearing all dtc's first...then see what comes back...then you can eliminate from there.

Sazexa
03-24-2018, 08:31 AM
If you're going to be selling the car, just sell it as it is. Realistically the price difference between a car with some engine codes vs. one without (assuming you trade it in a dealer) probably isn't going to be worth the cost you'd put out to fix it.

Jared12319
03-24-2018, 09:18 AM
If you're going to be selling the car, just sell it as it is. Realistically the price difference between a car with some engine codes vs. one without (assuming you trade it in a dealer) probably isn't going to be worth the cost you'd put out to fix it.

I've definitely had that thought. Initially it was a moral dilemma because the car was certainly not running well, and I didn't want to do that to someone. Lately, it is definitely running better. I'll be selling private party. I would get hosed at a dealership lol.

Jared12319
03-24-2018, 09:21 AM
My initial thought is the ECU is on its way out. Given your description of faults, several are unrelated and interdependent except in the ECU. I do remember reading some time back about ECU issues in earlier S5's. Then again, you said the car was rear ended. The parking brake control module is in rr quarter panel?? And the battery regulator module under the spare . Check comm b/t those modules and CAN comm as well. Im know some batt regulator modules are intergrated and some independent particular to specific models.
Also, If you didnt clear the preexisting dtc's , the ecu will ( or may)still try to compensate for them. Try clearing all dtc's first...then see what comes back...then you can eliminate from there.

That was a fear of mine, but I wasn't sure how exactly to test it. If I rapid scan my system, I would say 70-80% of my cars systems say "malfunction" and have some codes. Is there a quick way to clear all of these? Or do I need to go into each system and clear them?

Forgive me, I'm a noob to all of the scanning/reading data/etc.

jaypilot75
03-24-2018, 10:48 AM
First off, thank you for your recognition of making the ethical choice of not wanting to pass that along to another individual. I Definitly respect that decision. And of course your right, the dealership is gonna stick it to you, unless you plan on getting in a new(er) Audi.
Anyway, Im not too keen on scanners outside factory VAG or RossTech VCDS. VAG cars speak a different language all together that "general" scanners cant decipher. They can only provide the end dtc and have no way of talking to certain modules which is crucial for fault finding on VAG cars. If your scanner does CAN you typically can clear "all dtc's" if not, you may have chassis option scan capabilities which has a preset module scan.
Which you cant clear all dtcs without CAN comm. The problem with clearing dtcs one by one is if you have a dtc origin due to another module it will be like playing wack a mole.
I know you dont (as I wouldnt either) want to keep spending $ on a car you selling. But, if your scanner isnt cutting it....buy a rosstech cable....narrow down the problem, fix it and sell the cable to the new owner or sell it online. Trust me...you wont have any issues selling a genuine rosstech cable. You could probably just sell it on here very easily. For a couple hundred bucks you can buy one and they are hands down superior when stacked against any aftermarket cable. Bad ECU's can throw some bizzare unrelated codes.

Jared12319
03-24-2018, 10:55 AM
First off, thank you for your recognition of making the ethical choice of not wanting to pass that along to another individual. I Definitly respect that decision. And of course your right, the dealership is gonna stick it to you, unless you plan on getting in a new(er) Audi.
Anyway, Im not too keen on scanners outside factory VAG or RossTech VCDS. VAG cars speak a different language all together that "general" scanners cant decipher. They can only provide the end dtc and have no way of talking to certain modules which is crucial for fault finding on VAG cars. If your scanner does CAN you typically can clear "all dtc's" if not, you may have chassis option scan capabilities which has a preset module scan.
Which you cant clear all dtcs without CAN comm. The problem with clearing dtcs one by one is if you have a dtc origin due to another module it will be like playing wack a mole.
I know you dont (as I wouldnt either) want to keep spending $ on a car you selling. But, if your scanner isnt cutting it....buy a rosstech cable....narrow down the problem, fix it and sell the cable to the new owner or sell it online. Trust me...you wont have any issues selling a genuine rosstech cable. You could probably just sell it on here very easily. For a couple hundred bucks you can buy one and they are hands down superior when stacked against any aftermarket cable. Bad ECU's can throw some bizzare unrelated codes.

I appreciate that. And I'll be traveling for much of the next year, so as of right now I won't be looking into a newer Audi. You don't think the VAG401 tool would be sufficient? It seems to do everything I need it to; I just don't know everything about how to navigate it. I often refer to advice online if I'm trying to read something specific with the scanner.

Good point with the whack a mole reference, lol. My scanner may be able to do what you're mentioning; I just don't know how to access it. If it ultimately won't cut it, I'll pick up a different one.

Jared12319
03-26-2018, 04:21 PM
Got 4 codes popping up after driving for about 20 min today.

First it was an ESP error immediately followed by a parking break malfunction

After that I got a solid CEL, so I checked the codes:


006480- Radiator fan (V7), movement restricted/jammed. No fault type identified. This code has been around for months, haven't gotten to fixing the fan.

008569- Bank 2, system too lean off idle sporadic

000257- Mass Air Flow Sensor (G70) Implausible signal

005715- Please check DTC memory of ABS controller


Checked codes for the ABS and got the following:

01314- Engine control module
00473- Control module for elect. Park/hand brake (J540)




Here are my LTFT's as well:

Adaptation (Idle), Bank 1, Sensor 1: -2.25%

Adaptation (Partial), Bank 1, Sensor 1: 15.62%

Adaptation (Idle) Bank 2, Sensor 1: -2.72%

Adaptation (Partial) Bank 2, Sensor 1: 22.27%


Also went into the Gateway CAN module (no idea what this means frankly), and found 4 fault codes:

00457- Control module for network (J519) Open circuit

03041- Energy Management Active Value of resistance too great

02256- Quiescent Current Value of resistance too small

01314- Engine Control Module Open circuit




Again, I have no idea what much of this means in practice, but my hope is that it provides more insight into my problem. Thank you to everyone who's contributed to this thread in an attempt to help me solve my car problems. Your input is greatly appreciated.

Jared12319
03-28-2018, 09:40 AM
Bump. Crossing my fingers that someone can help with this. Considering pulling the intake manifold and doing a carbon clean + injector cleaning. I just don't see how that would solve the codes I'm getting.

jaypilot75
03-28-2018, 04:41 PM
Have you cleared all the dtc's....then scanned? Or is this what you had? The ecu will store any previous issues until it is cleared.
You also said something in your earlier post about unplugging the ecu. If you dont maintain constant proper voltage to the system (ie a charger or similar) this could (or may) cause dtc's as well. Due to undercharge. Anyhow, since you can access CAN...clear all dtc's...then scan.

jaypilot75
03-28-2018, 04:48 PM
Also, I know you said you replaced the battery....and I know it sounds strange but, if its not a genuine VAG battery I wouldnt trust it even though it may say it makes the same cap/cca/etc...
And another ? Did you code the new battery in via obd? If you didnt, the car/batt regulator may not know you put a new battery in.

jaypilot75
03-28-2018, 05:02 PM
Aannnddddd 1 more?...your coolant fan dtc has been around for months??? Is the car running hot at all?? I thought you were saying the dtc has been there but I was assuming the fan was still working

Jared12319
03-29-2018, 12:04 AM
Have you cleared all the dtc's....then scanned? Or is this what you had? The ecu will store any previous issues until it is cleared.
You also said something in your earlier post about unplugging the ecu. If you dont maintain constant proper voltage to the system (ie a charger or similar) this could (or may) cause dtc's as well. Due to undercharge. Anyhow, since you can access CAN...clear all dtc's...then scan.

To answer your questions:

- I couldn't figure out how to clear all of the codes at once on my handheld device. Do you have any tips? I imagine it would be much easier if I were using VCDS software on a computer. I can rapid scan the system and see which modules are malfunctioning, but I didn't see a button to clear all codes. I had to go into each module and do it. I cleared everything in the engine, Anti lock brake system, and parking brake modules. Later in the day I got an ESP light and parking brake malfunction light; haven't checked codes since.

- On two different occasions I put a new battery in, but no I did not code them. I read on various forums that you can get away without doing it, but if you're swapping a dead battery it may not recognize the new one is fully charged. Mine isn't dead, so I wouldn't think not coding would make much of a difference.

- I first saw that fan code months ago when a shop pulled it up (I could only read basic codes at the time with my OBDII scanner. Hadn't yet upgraded.) The temp gauge never gets above dead middle, but I have noticed it *feels* extremely hot under the hood. I'm not sure if the fan is working, as I'm not sure which one it is. If I turn on my AC, the fan on the passenger side kicks on, but the drivers side fan doesn't.

s5dan
03-29-2018, 12:27 AM
I had a problem with my s5 2015 model v6.
reving about 4k rpm the epc light would come on, a hose from the supercharger was torn, causing antifreeze to leak into the injectors.
if you have that model you should look into that.

Jared12319
03-29-2018, 04:10 PM
I had a problem with my s5 2015 model v6.
reving about 4k rpm the epc light would come on, a hose from the supercharger was torn, causing antifreeze to leak into the injectors.
if you have that model you should look into that.

Mines an 09, so 4.2L v8 as opposed to the newer V6. Thanks for the input thought!

Also, update: Today, after the ESP and parking brake malfunction came on (again), I shut down the car to run in a store, came out, and it started up fine but as soon as I put it in drive it died. Started right back up again and was fine. I recall this happening several months ago, but I thought it was just a fluke.

Jake@JHM
03-29-2018, 04:42 PM
I would replace the injectors. We see them fail ALL the time on these FSI V8s. Some start to leak, some stick ON, and some barley drizzle. You won't exactly get a rich or lean code because of a failing injector either.

Tyler8
03-29-2018, 04:53 PM
My friendís Ď08 S5 had very similar problems and like you, we tried everything to remedy it. Finally had to give up and bring it to the dealership. Even they couldnít correctly diagnose it, after throwing parts at it for 3 weeks they finally determined it was the ECU. New ECU fixed all the problems, I think it cost him like $1200 though


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Jared12319
03-29-2018, 05:15 PM
I would replace the injectors. We see them fail ALL the time on these FSI V8s. Some start to leak, some stick ON, and some barley drizzle. You won't exactly get a rich or lean code because of a failing injector either.

I appreciate the input! My next step was going to be pulling the injectors and doing a carbon clean. Since I'm a DIY guy, if the injectors aren't leaking I will likely just do a self cleaning. Really trying to get this all solved with minimal expenses so I don't take more of a loss on the car. If I get to the injectors and decide not to clean them myself, I was just going to pick up the kit you guys have and send mine in.

Jared12319
03-29-2018, 05:16 PM
My friendís Ď08 S5 had very similar problems and like you, we tried everything to remedy it. Finally had to give up and bring it to the dealership. Even they couldnít correctly diagnose it, after throwing parts at it for 3 weeks they finally determined it was the ECU. New ECU fixed all the problems, I think it cost him like $1200 though


Sent from my iPhone using Audizine (http://r.tapatalk.com/byo?rid=87676)

I really, really hope it isn't the ECU, lol. Is there any simple way to test whether this is the case without just replacing the ECU?

Jake@JHM
03-29-2018, 05:18 PM
I appreciate the input! My next step was going to be pulling the injectors and doing a carbon clean. Since I'm a DIY guy, if the injectors aren't leaking I will likely just do a self cleaning. Really trying to get this all solved with minimal expenses so I don't take more of a loss on the car. If I get to the injectors and decide not to clean them myself, I was just going to pick up the kit you guys have and send mine in.

It requires a special equipment to flow these injectors at their operating PSI to check for leaks. The only way you will know is if there is damage to your cylinder already. Most people melt a cylinder before figuring out the injector was the problem.

Jared12319
03-29-2018, 05:19 PM
Also, I'm consistently getting a MAF code now (signal implausible). Ughhhhhhh

Jared12319
03-29-2018, 05:20 PM
It requires a special equipment to flow these injectors at their operating PSI to check for leaks. The only way you will know is if there is damage to your cylinder already. Most people melt a cylinder before figuring out the injector was the problem.

Oh, lovely, lol. In that case, I will likely just send them in and buy the resealed & tested ones. I'm just hesitant to toss more money at the problem. To me, injectors don't explain many of the other problems I'm having. But I guess I could have a series of problems that are popping up independent of one another.

JoshDub
03-30-2018, 08:51 AM
Some people have found that when the maf goes it also trips the airbag/parking brake light. Wierd I know.

But I'd also put money on it being carbon build up and possibly injectors.

Jake@JHM
03-30-2018, 08:59 AM
Some people have found that when the maf goes it also trips the airbag/parking brake light. Wierd I know.

But I'd also put money on it being carbon build up and possibly injectors.

The engine mount solenoid also takes out the hpfp

Jared12319
03-30-2018, 10:32 AM
Some people have found that when the maf goes it also trips the airbag/parking brake light. Wierd I know.

But I'd also put money on it being carbon build up and possibly injectors.

I've read about that as well. Unfortunately I can't just swap a new/knowingly good MAF into it and see how it runs without completely replacing the part and possibly wasting money. If I unplug the MAF, the car immediately throws maf codes and an ESP/Parking brake light.

Is there any other way to test my MAF? When I read the live data, everything appears to be within spec.

Likely starting the teardown today. Does anyone have a guide for this? I found a guide for removing the intake manifold, but the only other guide I found had the photos removed from the guide so it's largely useless.

- - - Updated - - -


The engine mount solenoid also takes out the hpfp

Do you think this could be something I'm dealing with?

Also, do you have any idea why my O2 sensor voltages would be reading so high? Even with a brand new one in.

Jared12319
04-01-2018, 12:18 AM
Drove the car today a bit, and noticed a couple of things:

1) On a cold start, for about 1-2 min, the car was extremely sluggish upon acceleration. It was stuttering and shaking the whole car. Wasn't reading live data at the time, and no codes showed up. Car started feeling normal after a few minutes.

2) I went into measuring block 107, and noticed that at idle the test shows "system ok", but after accelerating and driving for a bit, it changes to "system not ok". Oddly enough, no codes on the dash, but I went and checked stored codes, and found 3. 2 of which have been around for a bit (radiator fan, and the ABS system code), but one was new. Is this essentially the same as a "System too lean bank 2" code?

004423: Oxygen (Lambda) Regulation Bank 2, system too lean.

Jared12319
04-06-2018, 05:37 PM
So, I decided to pull the intake manifold and do a carbon cleaning. Initially, I cleaned 2 ports by soaking with carb cleaner and using a brass wheel + dremel combo, along with dropping balls of steel wool in with carb cleaner and pushing them around with a screwdriver. This was for the harder to clean areas. It worked out fairly well (pics below), but ultimately took a lot longer than I would have liked for only cleaning 2 ports.

So, I'm picking up a media blaster + walnut shells to clean everything else. Along with that, I'm picking up an ultrasonic parts cleaner to at the very least clean all of the dirty parts I have. However, I may also use it to clean my own injectors.


Based on the pictures below, I have several questions;

1. Everywhere I saw online said I should only have 2 valves that aren't shut. On mine, it appears I have three which are open. Is this normal?

2. On cylinder 4, the valves appear to have some sort of copper/red colored portion on the uppermost part of the stem (see pic). None of the other valves had this. Not sure if broken or normal, lol.

3. Not seen in the photos, but is it normal for there to be tons of dirt/debris where the injectors are seated? Was able to get most of the dirt out with a shop back, but inevitably some had to have fallen in the holes. Pulling them out seemed harder than it should have been, but I'm not sure.

4. It appears there's an oil leak of some sort because of all the oil in the middle valleys. However, I can't see where it would come from. Initially I thought it was a combination of gas and coolant from when I was pulling everything apart, but the consistency seemed like just oil

5. On a couple of injectors, it appears the stem is covered in white residue. I'm not sure what this means, and can't find info online. Any ideas?

6. Do the injector seals look shot? Or do you think I can reuse them? I would reseal them, but $20-$40 per injector for some o-rings seems steep.




https://i.imgur.com/UDwnVNU.jpg
https://i.imgur.com/chujW2Q.jpg
https://i.imgur.com/d4vqYgO.jpg
https://i.imgur.com/9Ns2j8K.jpg
https://i.imgur.com/rmkxiFE.jpg
https://i.imgur.com/16pNM9y.jpg
https://i.imgur.com/VHMegVe.jpg

new2s5
04-07-2018, 08:30 AM
YUCK, that's alot of buildup! I hope this solves your problems.

plat
04-07-2018, 10:12 AM
Good work!

plat
04-07-2018, 10:24 AM
4. It appears there's an oil leak of some sort because of all the oil in the middle valleys. However, I can't see where it would come from. Initially I thought it was a combination of gas and coolant from when I was pulling everything apart, but the consistency seemed like just oil

5. On a couple of injectors, it appears the stem is covered in white residue. I'm not sure what this means, and can't find info online. Any ideas?

6. Do the injector seals look shot? Or do you think I can reuse them? I would reseal them, but $20-$40 per injector for some o-rings seems steep.



If my memory serves me right, the V8 engine in the S5 had some issues with cylinder head gaskets allowing oil to leak out especially as the engine gets older.

As for the injectors and their gaskets, your car is already 90,000 miles old. Just spend the money and get new injectors and gaskets. Those O-rings are not just plain O-rings. They need to withstand extreme heat and pressure. Spend the $$ and get them changed. Do not be stingy. You've already gone through the a lot of effort to do the carbon cleaning, don't botch the job because you feel stingy. You cannot own an Audi and then cheap out on stuff.

pocketmaster
04-07-2018, 01:55 PM
Jared.... It looks like you may have a valley pan gasket leaking as well. It could also be the oil filter housing gasket, but the pic only shows the valley pan cover.

Jared12319
04-09-2018, 11:17 AM
Quick question everyone; how do you recommend closing the valves that are currently open? I've seen people use the crank bolt, but it appears I would need to remove my bumper for that method. I've seen others put the car in gear, remove spark plugs, and push the car or lift a wheel and turn, but I have an automatic.

Would I be able to close them by trying to turn over the motor while having someone watch the valves? My only fear is spraying fuel everywhere, and I'm not sure where my fuel pump fuse is.

- - - Updated - - -


Jared.... It looks like you may have a valley pan gasket leaking as well. It could also be the oil filter housing gasket, but the pic only shows the valley pan cover.

I believe I'm leaking from both. Just ordered new ones today. Thank you!

- - - Updated - - -


YUCK, that's alot of buildup! I hope this solves your problems.

Me too!! Lol

Jared12319
04-10-2018, 11:49 AM
Bump. Going to clean the other 3 ports today, just not sure if I'm safe turning over the engine with my push button start to close the valves.

Darel
04-10-2018, 01:08 PM
Sorry I wish I could answer that, but I'm curious myself. There has to be a way to crank it over, is access to the crank bolt really that bad? What about a screwdriver in the teeth of the flexplate? I have been wondering this since I got my wife's DI Mercedes E350, and have been shopping for an S5. I think either the car would immediately know something is wrong when you turn it on and wouldn't crank at all, or it would keep cranking over and over, or it would throw a code that you can't clear that may or may not throw you off your hunt for all of the OTHER codes when the car is back together.

In any case I'm watching this closely. I'd definitely be trying to turn it physically, either with the crank bolt or with the flexplate. Do these cars have a scattershield that can be removed and you can put a wrench on the flexplate, torque converter, or whatever else is hanging out at the back of the engine?

I've also had luck (on other cars) just pulling the plugs and using the accessory belt to turn it over. Maybe a big wrench on the alternator if it's accessible.

Jared12319
04-11-2018, 01:27 PM
So an update. Iíll try to keep it quick, lol.

- Walnut shell blasting was a nightmare. Made a huge mess and frankly, I preferred doing soak & scrub. Attempted to make a port adapter and try again, but was still not working very well and making a mess (albeit a smaller one). Gave up on blasting and went back to soak and scrub.

- Unfortunately I couldnít get my car into service position to access the crank bolt. Parked on a sandy/rocky surface so a jack isnít feasible, and I didn't want to turn on the car so I could turn my wheels & access the bolts under my fender liners.

- To close the 3 open ports, I put a cup under the main fuel line and had my girlfriend start the car and stop it immediately. It worked for 2 out of the 3 ports! Initially, there was a loud pop, but it was because I left a port sealed with tape and the suction from the valves created the pop sound, lol. Thankfully nothing got sucked in.

- After cleaning the two now closed ports, I hopped in myself and hit the start button. No pop this time (lol), and the car kept cranking until I hit stop (about 5-7 seconds after starting). It closed the last port!




Recent problems Iíve encountered:

- To clean the upper parts of my ports, Iíve been using a Dremel with a brass or steel wheel. Unfortunately, the fibers shoot off and even if you blow with air, some get stuck around the rim of the valves. These were a huge PITA to get out. Used a combo of air, a pick tool, and a small magnet tool. Unfortunately, I wasnít as diligent with the first 4 ports I cleaned. So some fibers likely fell in. Could this cause any serious issues?

- While cleaning with the Dremel, sometimes it would pop out of the port towards the top and catch the surface where my intake manifold gaskets sit, could this negatively impact the seal and cause leaks? The scratches aren't very deep.



Will attach pics today!

Darel
04-19-2018, 03:01 AM
I hope a lack of updates means you're out driving and enjoying your car!

Jared12319
04-20-2018, 10:44 PM
Alright guys, hereís an update on the situation. Iím going to outline some problems I ran into during the carbon clean in hopes that someone running across this in the future can avoid the same problems.


Problems:

- When taking out the eyelet used to lift up the engine on the front left of the car, I ended up having to cut a bolt with a Dremel because it got stuck. When you take out the bracket, there are two bolts. Theyíre not T50, but thatís what was recommended (and what I used) to take them out. However, the one on the front of the engine didnít have enough space to back out all of the way. It ended up colliding with another bolt that holds on some sort of bracket above the fan assembly. Long story short, I was in a position where the only way to get it out was to cut it. I was able to refit another bolt after everything was said and done, but nonetheless still annoying.

- Getting the 4 connectors off the front of the intake manifold was damn near impossible. Even after disconnecting everything in the back, I had basically no play to work with the wires. Everything was zip tied down, and I couldnít reach the zip ties to cut them. With a ton of patience, some pick tools, and some very long flathead screwdrivers, I eventually got them undone.

- When removing the bottom two hoses on the throttle body housing, one of them snapped clean off even though I had removed the clamp. In the end, I decided not to buy a new unit (itís only $40 though, so even if I needed to it wouldnít have been bad at all). I decided to plastic weld it back together, and finish off with plastic epoxy for insurance. Everything sealed great, and went back together just fine.

- I forgot to disconnect my battery before doing the job, so my battery was entirely drained by the end of the job, and I had about 40 codes to clear, lol.

- While putting everything back together, I thoroughly cleaned the throttle body. Well, perhaps that was a bad idea. I speculate it was because of how much I moved the plate back and forth, but once I went to start the car it wouldnít start. Or, it would start but run extremely weird, give me no throttle response, and then die. After some research, I did a throttle body alignment with my scanner, and boom, it started up/ran great.



You can read the other problems I ran into on the last page. They include walnut shell blasting not working out, and Dremel bit wires flying everywhere, lol.


A couple of other notes worth mentioning:

- I decided to clean the injectors myself. After a lot of research, the conclusion I reached was injectors rarely ďgo outĒ, and are more often just dirty/clogged up/etc. Checked resistance on all injectors and they looked good, so I continued on my own. The process was a combined hour+ in an ultrasonic bath (not pulsing in the bath), which cleaned up the outsides nicely. After that, I cleaned the internals with the common method seen online where you use carb cleaner and a rigged pulsing unit. No, I did not replace the o-rings or seals. I know I will probably get flak for that, but itís worth letting you know about.

- I also reused my intake manifold gaskets. Cleaned in an ultrasonic bath, and they looked like new. Of course, I inspected for tears/breaks. If I had any, I would've bought new gaskets.

- I replaced my oil filter housing gasket, as well as valley pan gasket per someones recommendation on here. I think those were likely the causes of the oil I was seeing when I took off the intake manifold. Not sure what failed, but the OFHG was decently brittle, so perhaps that was it.


Letís move on to how the car is now, what problems still exist, and then I will post images. So far, Iíve noticed;

- Way more power. The car pulls harder than when I got it at 49k miles (currently at 92.5k). If I had to put a number on it, it feels like I regained 40+ HP and TQ. Take those numbers with a grain of salt, but man it pulls a lot better and smoother.

- No more misfires under any conditions on any cylinders. Remember, for a period of time cylinder 8 would misfire hundreds of times within a minute.

- No more lean codes under any conditions, and Iíve driven the hell out of the car since doing this.

- In addition, there are no apparent problems from the job, so yay for that.


While that all sounds great, I am still noticing a couple of things:

LTFTís for under load are still looking pretty lean. Both banks hover around 10-15%, but never get high enough to trip a code. However, when I read STFTís, everything looks fine much of the time. It mostly gets lean under slight load. Whenever Iím on it, the fuel trims are fine. Any thoughts on what this could be?

Iím still getting a MAF Signal implausible code. 99% of the time it comes up when Iím cruising on the highway around 60-70 mph. A couple of times it has come on crushing at 30-35, but rarely. Is my MAF just bad? Iíve cleaned it, so I know it isnít dirty.

Jared12319
04-25-2018, 12:49 PM
Bump!

Jake@JHM
04-25-2018, 01:06 PM
Bump!




- I decided to clean the injectors myself. After a lot of research, the conclusion I reached was injectors rarely ďgo outĒ, and are more often just dirty/clogged up/etc. Checked resistance on all injectors and they looked good, so I continued on my own. The process was a combined hour+ in an ultrasonic bath (not pulsing in the bath), which cleaned up the outsides nicely. After that, I cleaned the internals with the common method seen online where you use carb cleaner and a rigged pulsing unit. No, I did not replace the o-rings or seals. I know I will probably get flak for that, but itís worth letting you know about.

That method for cleaning won't do much. You need to be able to spray them at operating PSIs. We work with one of the only companies in the US who are able to do this on a bench. Additionally, the electronics fail inside the injector which cause most of the problems with them.

They don't "rarely" go out either, the FSI cars eat through injectors due to the environment and conditions they sustain on a daily bases.

volvofan
04-25-2018, 01:26 PM
Iím still getting a MAF Signal implausible code. 99% of the time it comes up when Iím cruising on the highway around 60-70 mph. A couple of times it has come on crushing at 30-35, but rarely. Is my MAF just bad? Iíve cleaned it, so I know it isnít dirty.

Glad to hear the carbon cleaning seems to have cured most of your ailments!

Regarding the MAF signal code... I had some problems with my air intake that resulted in similar symptoms. The air filter was not properly secured to the MAF housing, so I would get P0101 as well as parking brake, TPMS, stability, and a whole host of other warnings that would all pop up occasionally. Securing the air filter cured almost all of that, including the "signal implausible" code. One other thing to try before attempting to replace the MAF: how did you clean it? Did you spray MAF sensor cleaner into all the little bitty holes? You can only get at so much on that MAF. Try this: Get some GOOD rubbing alcohol (like, 99% pure... order it online) and fill a gallon ziploc bag with about a quart of the stuff. Toss your MAF in there, seal the bag, and shake the dogshit out of it for about five minutes. Take MAF out, reinstall, save the rubbing alcohol if you want because it probably won't be too dirty, and see if that helps.

Hope you're enjoying your S5 again! Thanks for posting up some hard lessons learned. You might just save some other AZers the pain you've experienced :)

-Jon

Jared12319
04-28-2018, 09:13 AM
Glad to hear the carbon cleaning seems to have cured most of your ailments!

Regarding the MAF signal code... I had some problems with my air intake that resulted in similar symptoms. The air filter was not properly secured to the MAF housing, so I would get P0101 as well as parking brake, TPMS, stability, and a whole host of other warnings that would all pop up occasionally. Securing the air filter cured almost all of that, including the "signal implausible" code. One other thing to try before attempting to replace the MAF: how did you clean it? Did you spray MAF sensor cleaner into all the little bitty holes? You can only get at so much on that MAF. Try this: Get some GOOD rubbing alcohol (like, 99% pure... order it online) and fill a gallon ziploc bag with about a quart of the stuff. Toss your MAF in there, seal the bag, and shake the dogshit out of it for about five minutes. Take MAF out, reinstall, save the rubbing alcohol if you want because it probably won't be too dirty, and see if that helps.

Hope you're enjoying your S5 again! Thanks for posting up some hard lessons learned. You might just save some other AZers the pain you've experienced :)

-Jon

Thank you for the input on the MAF code! I'm going to look at the air filter and see if it's correctly fitted. To be clear, are you talking about the clips that connect that housing to the MAF not being secure? Or the air filter itself not being secure in its pocket with the o-ring?

I sprayed it as well as I could on multiple occasions. If the air filter isn't the problem, I'll do that next.

Also, some bad news. Last night I got a system too lean bank 1 code. Looked at LTFT's and bank 1 was about 21%, while bank 2 was 18%

Not completely bummed yet, since I'm *hoping* the MAF is causing these issues. No problem under idle; fuel trims are totally normal. So I don't suspect a vacuum problem.

Thank you!! I figured if it helps one person down the line it was worth it.

Jared12319
05-03-2018, 12:39 PM
Update:

Since my last post, I pulled out my air filter and checked its fitting to the MAF housing. As I was taking it apart, I remembered how I had trouble fitting the o ring properly when I replaced the filter months back. Right when I pulled the filter out, the o-ring popped off. What I had done was wedge the o-ring in between the gap on the MAF housing where the filter fits in, and apparently wedged the filter in after it, lol. This time around, it seemed like it would make more sense to have the o-ring around the base of the air filter. So I did that, and reattached everything. It certainly went together easier than last time. Drove around for a day and no MAF codes!! Unfortunately, the next day as I was entering the freeway I got my ESP and parking break malfunction errors. Checked the codes and you guessed it; MAF signal implausible, plus check DTC memory for ABS.

At this point, the only thing I can think of is that I have a fried MAF. Any other thoughts?

Jared12319
05-08-2018, 09:46 AM
Bumping this thread again. Any ideas? As of right now, the only problem I'm getting is the MAF signal implausible code that trips my ESP + parking brake light. My fear is throwing in a new MAF and having the same problem. Any thoughts on what to check? I read the MAF values while driving and everything seems within spec. 99.9% of the time I only trip a code while getting on the freeway at ~1/2 throttle, or I'm coasting around 60-70 for a minute or two. After I clear the code once, it usually doesn't come back until the next time I drive.

Would an ECU reset help? I read that I could just disconnect the negative terminal for 20+ min and it would reset, but after I did that I still have a bunch of malfunctions in various modules. In other words, I don't think it reset. Do I need to disconnect and hold together the positive and negative cable for 20 min? I also read that somewhere.

Jared12319
05-15-2018, 10:20 AM
Update: a few days ago while driving I got an "engine coolant too low, pull over." warning. After checking around I did see that in fact, my overflow tank was missing about 80% of the coolant. I've had the tank itself crack on the inside, causing a similar leak; so I thought that may have been the cause.

Anyway, I drove around for a couple days, trying to pinpoint exactly where the leak was coming from. It was prettt significant. If I parked on a decline or incline, I would lose a couple cups at least.

Then it hit me. I'm not sure if I mentioned it here, but during the carbon clean I broke a piece of the throttle body flange (part below), while taking the coolant hose off the underside. It just snapped right off, leaving the remaining piece inside the hose. Being impatient, instead of just ordering a new one, I decided to plastic weld the piece back on and finish off with high heat epoxy.

Well, after enough heating up and cooling down that piece became extremely brittle and was basically just sitting together without a good seal. I couldn't verify this at first, but it made the most sense.

So, I ordered the part and started taking the car apart once again. After getting the intake hose and throttle body off, I realized there was absolutely no way I was getting this thing off without removing the entire intake again. There wasn't enough room to reach bolts otherwise.

After removing the intake, it was very easy to remove/install the new part. Just irritating because I could have avoided the whole fiasco if I were a bit more patient. I will say that after you take the intake off once, it's WAY easier the second time.

Also, I am shocked at how quick the carbon builds back up. All valves had a thin and dry black coating, with most of them having a bit of the wet/slimy looking carbon on them.


Part:
https://www.autohausaz.com/pn/OE-079133021C?utm_source=google&utm_medium=cpc&utm_campaign=frooglePN&utm_term=079133021C&gclid=CjwKCAjwiurXBRAnEiwAk2GFZq-bcjBObWLnHrzRecvYdkuOZigPhgMOjYHcJRF0rhiLgQHfs_s68 RoC0-QQAvD_BwE

Jared12319
05-28-2018, 09:27 AM
Bump. MAF code hasn't come on for more than a week regardless of driving conditions. Fingers crossed the problem sorted itself out.

Jared12319
03-23-2019, 11:05 AM
Bump. MAF code hasn't come on for more than a week regardless of driving conditions. Fingers crossed the problem sorted itself out.

Update:

Recently the MAF code came back, as well as a lean code for both banks.

Even if I reset the codes, they come back every time I drive the car for more than 10 min. Not sure where to proceed from here. My first thought is to clean the MAF, make sure there are no leaks areound it, and see if that helps.

If not, I'll buy a new MAF and try that.

If all else fails, I'll be pulling the intake manifold again and getting new injectors.

mvigil
03-24-2019, 01:47 AM
I understand vehicles operate differently given numerous variables (i.e., maintenance history, previous owner care, altitude, etc.), but I thought I'd share my experience as it might provide some benefit.

For starters my S5 has approximately 168,000 miles and went in for major service a couple months ago. Carfax presented all maintenance intervals were completed prior to my ownership. Vehicle was running fine prior to service with no CELs. Previous owner mentioned car was due for a carbon clean. I took it to a reputable indie shop however, after two months of being in the shop it was returned to me with a CEL and ESP light on. Shop wasn't sure what the issue was. Work that was completed consisted of a carbon clean, rebuilt injectors and spray pattern tested by Bosch, fuel system clean, front crankshaft seal replaced, new serpentine belt, oil pan resealed, new valve cover seals, new in tank LPFP, new fuel control module, new spark plugs, air filter, oil change. After spending a ridiculous amount of money on this service and having it returned to me running worse than when I dropped it off, I limped it home where it sat in the garage. Thankfully it is not my daily driver.

In my free time I started diagnosing issues myself (working on cars is nothing new to me). I was getting a code for lean bank 2 and a MAF code as well. I decided to replace both HPFPs and the MAF. This cleared the lean code but still had the MAF code. Also, I knew something was off as the car would run fine, but when I would depress the clutch to put in gear or in neutral, the RPMs would jump up before dropping down. I found that the large O-ring that fits between the air filter and MAF was missing so I put one in. Additionally, I decided to purchase a 034 Motorsports intake tube. After installing these parts instead of clearing the codes from the OBD-II, I disconnected the battery for about 30 minutes. Problem solved and no CEL or ESP since.

Jared12319
03-25-2019, 03:11 PM
I understand vehicles operate differently given numerous variables (i.e., maintenance history, previous owner care, altitude, etc.), but I thought I'd share my experience as it might provide some benefit.

For starters my S5 has approximately 168,000 miles and went in for major service a couple months ago. Carfax presented all maintenance intervals were completed prior to my ownership. Vehicle was running fine prior to service with no CELs. Previous owner mentioned car was due for a carbon clean. I took it to a reputable indie shop however, after two months of being in the shop it was returned to me with a CEL and ESP light on. Shop wasn't sure what the issue was. Work that was completed consisted of a carbon clean, rebuilt injectors and spray pattern tested by Bosch, fuel system clean, front crankshaft seal replaced, new serpentine belt, oil pan resealed, new valve cover seals, new in tank LPFP, new fuel control module, new spark plugs, air filter, oil change. After spending a ridiculous amount of money on this service and having it returned to me running worse than when I dropped it off, I limped it home where it sat in the garage. Thankfully it is not my daily driver.

In my free time I started diagnosing issues myself (working on cars is nothing new to me). I was getting a code for lean bank 2 and a MAF code as well. I decided to replace both HPFPs and the MAF. This cleared the lean code but still had the MAF code. Also, I knew something was off as the car would run fine, but when I would depress the clutch to put in gear or in neutral, the RPMs would jump up before dropping down. I found that the large O-ring that fits between the air filter and MAF was missing so I put one in. Additionally, I decided to purchase a 034 Motorsports intake tube. After installing these parts instead of clearing the codes from the OBD-II, I disconnected the battery for about 30 minutes. Problem solved and no CEL or ESP since.

I greatly appreciate your response. I'm sorry to hear all the trouble you went through having your car in the shop.

Only position I don't want to be in is throwing parts at it. I was about to say screw it and order some rebuilt injectors, but then realized it could easily be another issue.

It's interesting you fixed the problem with those few parts. I never considered HPFP's- I recently had a low fuel pressure code plus horrible cold starts, but a new LPFP fixed that.

One thing that makes me think the lean code is not my injectors, is that even after I cleaned them (albeit not professionally) it still ran lean, just not enough to trip a code (see previous posts). Or, it could also mean I have really bad injectors I suppose, lol.

I wonder if your problem was a vacuum leak or HPFP problem. In earlier posts I mentioned how I had reinstalled the air filter ring wrong, but fixing it didn't change anything (unless, of course, I never fixed it.)

The ring goes between the filter and the air box, right? And then the MAF fits flush to the airbox and clips in with nothing in between it and the housing?

Right now my thought is to:

- Test for a vacuum leak (paint bucket method), to rule that out as the issue. Did this during the carbon clean and never found anything, but who knows.
- Reinstall air filter O-ring if I did it wrong.
- Order a different MAF, to see if that solves the MAF implausible signal code (and perhaps even the lean codes)

If none of that works, I suppose the next steps are injectors and/or HPFPs. Obviously I'd prefer to do the more expensive parts last.

My anxiety is ramping up about the issue, because it is my daily. I (stupidly) drive the car a lot despite these problems. Constantly clearing codes every time I drive. I really don't want damage from running lean all the time, and I'm not sure how well the car is correcting for that.

To recap, the current issues are:

Lean bank 1 off-idle
Lean bank 2 off-idle
MAF Signal implausible (G70)

These codes come on nearly every time I drive more than a few minutes.

Jared12319
03-31-2019, 03:47 PM
UPDATE:

Today I ordered a new MAF, and also tested for vacuum leaks (smoke method with a transfer pump.)

I didn't expect much, but to my surprise, I have a vacuum leak!! It's right where the intake hose meets the throttle body. It wasn't major, but it was noticeable.

I hope this solves at least one of my problems. If not, I'm not too concerned. All I had to do was reposition the hose and tighten the clamp!

I'll post another update soon!