A4 B7 engine turns but does not start

[marlboro]

I have a stock A4 B7 2.0T, the engine just switched off while driving and does not start any more. I towed the car home, opened the cam belt inspection window. The cam belt is intact. When I try to start the the car, the engine turns slowly but does not start. There is no check engine light. I have a full Vagcom and here are the errors when I scanned it immediately after this happened:

001287 - Idle Control System RPM
P0507 - 001 - Higher than Expected.
Freeze Frame:
Fault Status: 01100001
Fault Priority: 0
Fault Frequency: 35
Reset counter: 255
Mileage: 310966 km
Time Indication: 0

Freeze Frame:
RPM: 922 /min
Load: 13.7 %
Speed: 0.0 km/h
Temperature: 87.0 C
Temperature: 49.0 C
Absolute Pres.: 840.0 mbar
Voltage: 13.716 V

000665 - Boost Pressure Regulation
P0299 - 002 - Control Range Not Reached
Freeze Frame:
Fault Status: 01100010
Fault Priority: 0
Fault Frequency: 1
Reset counter: 255
Mileage: 317355 km
Time Indication: 0

Freeze Frame:
RPM: 3685 /min
Load: 61.9 %
Speed: 55.0 km/h
Temperature: 61.0 C
Temperature: 11.0 C
Absolute Pres.: 850.0 mbar
Voltage: 14.224 V

012555 - Low Pressure Fuel regulation
P310B - 004 - Fuel Pressure Outside Specification - Intermittent
Freeze Frame:
Fault Status: 00100100
Fault Priority: 0
Fault Frequency: 2
Reset counter: 255
Mileage: 317581 km
Time Indication: 0

Freeze Frame:
RPM: 859 /min
Load: 63.1 %
Speed: 0.0 km/h
Temperature: 93.0 C
Temperature: 55.0 C
Absolute Pres.: 850.0 mbar
Voltage: 13.335 V

000010 - Camshaft Positioner (Bank 1 Intake)
P000A - 008 - Slow Response - Intermittent
Freeze Frame:
Fault Status: 00101000
Fault Priority: 0
Fault Frequency: 1
Reset counter: 255
Mileage: 318185 km
Time Indication: 0

Freeze Frame:
RPM: 991 /min
Load: 19.6 %
Speed: 0.0 km/h
Temperature: 24.0 C
Temperature: 15.0 C
Absolute Pres.: 850.0 mbar
Voltage: 14.224 V

004688 - Fuel Level too Low
P1250 - 008 -
Freeze Frame:
Fault Status: 01101000
Fault Priority: 0
Fault Frequency: 1
Reset counter: 255
Mileage: 318626 km
Time Indication: 0

Freeze Frame:
RPM: 957 /min
Load: 13.3 %
Speed: 0.0 km/h
Temperature: 93.0 C
Temperature: 41.0 C
Absolute Pres.: 850.0 mbar
Voltage: 13.843 V

000835 - Camshaft Position Sensor (G40)
P0343 - 001 - Signal too High
Freeze Frame:
Fault Status: 01100001
Fault Priority: 0
Fault Frequency: 1
Reset counter: 255
Mileage: 318637 km
Time Indication: 0

Freeze Frame:
RPM: 2592 /min
Load: 9.0 %
Speed: 39.0 km/h
Temperature: 89.0 C
Temperature: 36.0 C
Absolute Pres.: 840.0 mbar
Voltage: 13.843 V

I thought, it might be the in-tank fuel pump but I opened the inlet of the HPFP and when I try to start the car, fuel comes out. I checked all the fuses and there is nothing blown. I opened the ECU compartment and checked the fuses under the ECU - they are fine. I also swapped the 2 relays under the ECU (I believe one of them is for the fuel pump) but no difference. I measured them with multimeter and both show about 55 Ohms.

Next, because of the codes above about the camshaft sensor errors, I bought a new camshaft sensor, replaced it but the issue is still the same.

After that, I bought a new crankshaft position and sensor, even if there was no code for it, replaced that one as well but still no start.

After I cleared the above codes and after multiple starting attempts, there is no any error codes when I scan it again with Vagcom.

The only thing left is maybe a faulty HPFP but I don't have another one to test with and a new one is too expensive just to try. Is there a way to test it and know for sure, if it's faulty? If I open the banjo bolt and crank the engine, is fuel supposed to come out without the car starting?

I'm running out of ideas. Any recommendations of what to test and try next?

[Theiceman]

can you see if the intake cam is turning when you peer through the oil fill hole ( not the exhaust cam ) .. i fear the worse and your cam chain tensioner has failed and snapped the cam chain.

[marlboro]

can you see if the intake cam is turning when you peer through the oil fill hole ( not the exhaust cam ) .. i fear the worse and your cam chain tensioner has failed and snapped the cam chain.

Just checked - the intake cam does not move. The cam belt is still turning. So what now? Is the engine completely destroyed or it could be saved, if I put a new chain and tensioner?

[vce1232000]

Just checked - the intake cam does not move. The cam belt is still turning. So what now? Is the engine completely destroyed or it could be saved, if I put a new chain and tensioner?

most likely you have some bent valves. Will need need to remove head. replace valves, seals & new timing chain parts.

[Theiceman]

Just checked - the intake cam does not move. The cam belt is still turning. So what now? Is the engine completely destroyed or it could be saved, if I put a new chain and tensioner?

yeah thought so . if it happened on the highway you very likely have bent intake valves.. as mentioned head has to come off..
if you are paying for the work, may be time to scrap the car at labour prices these days. even replacement motors of unknown condition are getting expensive .


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[Theiceman]

btw how many miles ?? 170k or so ?

oh never mind I just saw 193k.. yup delrin shoes came off tensioner, jammed in chain and snapped it.


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[marlboro]

yeah thought so . if it happened on the highway you very likely have bent intake valves.. as mentioned head has to come off..
if you are paying for the work, may be time to scrap the car at labour prices these days. even replacement motors of ink own condition are getting expensive .


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It didn’t happen on the highway. It happened on a small road under acceleration but with relatively slow speed. Is there a way to check if the engine is salvageable without removing the head? I’m planning to do the work on my own, although I’ve never done something like that before. Most I have replaced the cam belt, vacuum pump and cleaned the valves on this car before.

[Theiceman]

It didn’t happen on the highway. It happened on a small road under acceleration but with relatively slow speed. Is there a way to check if the engine is salvageable without removing the head? I’m planning to do the work on my own, although I’ve never done something like that before. Most I have replaced the cam belt, vacuum pump and cleaned the valves on this car before.

it happened to my car and I saved it without removing the head.. look up my " that's all she wrote" thread..

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[Jayz691]

can you see if the intake cam is turning when you peer through the oil fill hole ( not the exhaust cam ) .. i fear the worse and your cam chain tensioner has failed and snapped the cam chain.

I was thinking the same exact thing..

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[Jayz691]

Most likely ya bent some intake valves. Very slim chance ya didn't, buy its possible. You could do the cam chain service, then test compression. Maybe pull the IM off, and have a look at the intake valves, from the back side. May see something obvious. Or just pull the head, and go over it all. Chain snapping isn't as bad as the belt, at least the exhaust side stays in time.
Most likely the chain snapped, but, a few other things could have happened too. Seen oil pressure drop, and exhaust cam snap. Similar results. Keyway sheer on the cam adjuster. But more likely chain failure.
Good luck.

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[marlboro]

Thank you Theiceman, vce1232000 and Jayz691 for the replies. I will start tearing it down and update the thread. If I sell it now, I have to sell a car with a broken engine. If I try and don't succeed, I will still sell a car with a broken engine but I'll know at least I tried

[PhireSideZA]

Bad luck bud! Locally you can probably source the cam chain kit for around ZAR4000 or so which seems to be the going rate. I think vagcafe sells them, and they are reputable. Boss Auto Spares, Goldwagen and OnlineCarParts would be your other go-to's for needed parts that a place like Alert can't supply.

I'm going to slightly hijack your thread to ask a really random question, but approximately how many kilos did you get off a full tank? Odd but I have a few reoccurring fault codes that you are getting as well, namely P0299, P310B, and P000A. In my case, P0299 is likely because my wastegate started rattling recently, P310B could be the G410 sensor on the HPFP and P000A from the N205 valve that sits on the head towards the back of the engine.

https://www.vagcafe.com/product/ecs-...r-service-kit/

[Theiceman]

Most likely ya bent some intake valves. Very slim chance ya didn't, buy its possible. You could do the cam chain service, then test compression. Maybe pull the IM off, and have a look at the intake valves, from the back side. May see something obvious. Or just pull the head, and go over it all. Chain snapping isn't as bad as the belt, at least the exhaust side stays in time.
Most likely the chain snapped, but, a few other things could have happened too. Seen oil pressure drop, and exhaust cam snap. Similar results. Keyway sheer on the cam adjuster. But more likely chain failure.
Good luck.

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I'm think adjuster key is toast but that can be fixed

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[Theiceman]

he was getting fuel codes because there was no cam motion to activate his HPFP.

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[vce1232000]

Thank you Theiceman, vce1232000 and Jayz691 for the replies. I will start tearing it down and update the thread. If I sell it now, I have to sell a car with a broken engine. If I try and don't succeed, I will still sell a car with a broken engine but I'll know at least I tried

most diy'er buyers shy away from purchasing a vehicle that has been taken apart & not fixed. But they will more likely purchased as-is if that the case. Its not really a hard job. There are plenty of video & link resources that you can research to do. Its even on AZ here on the search bar. good luck with it either way....

[Jayz691]

I'm think adjuster key is toast but that can be fixed

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Well, maybe we'll get to find out. My bet is on a snapped chain, but very well could be any of them.

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[Theiceman]

the order of operations.
pad breaks off tensioner, pad get jammed in chain, stops... exhaust cam tears off key in adjuster, chain snaps . intake cam stops piston hits valves

basically... carnage

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[PhireSideZA]

he was getting fuel codes because there was no cam motion to activate his HPFP.

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I thought that too, but his fuel codes were at 317581km and the last fault code stored relating to the camshaft sensor was a few hundred miles later at 318637km. But maybe they are related in some way since the HPFP runs off the intake cam.

[Theiceman]

I thought that too, but his fuel codes were at 317581km and the last fault code stored relating to the camshaft sensor was a few hundred miles later at 318637km. But maybe they are related in some way since the HPFP runs off the intake cam.

yes and the actual timing is very important,, as the timing on the lobes is synched to the firing of the solenoid on the pump .. i would say this is not a good baseline unit to check against ;)

[marlboro]

Bad luck bud! Locally you can probably source the cam chain kit for around ZAR4000 or so which seems to be the going rate. I think vagcafe sells them, and they are reputable. Boss Auto Spares, Goldwagen and OnlineCarParts would be your other go-to's for needed parts that a place like Alert can't supply.

I'm going to slightly hijack your thread to ask a really random question, but approximately how many kilos did you get off a full tank? Odd but I have a few reoccurring fault codes that you are getting as well, namely P0299, P310B, and P000A. In my case, P0299 is likely because my wastegate started rattling recently, P310B could be the G410 sensor on the HPFP and P000A from the N205 valve that sits on the head towards the back of the engine.

https://www.vagcafe.com/product/ecs-...r-service-kit/

Howzit, I'm not 100% about the tank mileage because I haven't really measured it recently. I have done it but a while ago and it wasn't heavy on fuel at all. And I haven't noticed any fuel consumption increase lately. I think, I can do at least 700km on a tank, driving on the highway. Thanks for the link but I don't really need the full kit. I have already the valve cover gasket and new valve cover bolts because I noticed the P0299 code sometime ago. My valve cover has been leaking recently and I was planning to change the gasket anyway. I was hoping the P0299 is related to it. When I tested the PCV, I can't blow through it, so it should be OK.

most diy'er buyers shy away from purchasing a vehicle that has been taken apart & not fixed. But they will more likely purchased as-is if that the case. Its not really a hard job. There are plenty of video & link resources that you can research to do. Its even on AZ here on the search bar. good luck with it either way....

Thank you!

I thought that too, but his fuel codes were at 317581km and the last fault code stored relating to the camshaft sensor was a few hundred miles later at 318637km. But maybe they are related in some way since the HPFP runs off the intake cam.

Yes, I also noticed my fuel codes were at a previous mileage and not when this happened. I'm also a bit puzzled by them.

Started taking it a bit apart after work today. At least the cam follower is intact but I have been changing it at regular intervals.

[Theiceman]

when you take that rear timing cover off... you will see the carnage ..

that is a lot easier with a micro ratchet and bits BTW.

[marlboro]

when you take that rear timing cover off... you will see the carnage ..

that is a lot easier with a micro ratchet and bits BTW.

Now you are scaring me

Yes, I know. I have a micro ratchet. I bought it before when I was doing the vacuum pump and the coolant flange.

[vce1232000]

when you take that rear timing cover off... you will see the carnage ..

that is a lot easier with a micro ratchet and bits BTW.

agree... I also remove the vacuum pump 1st. This makes it easier to get to the screws

[PhireSideZA]

Cool @marlboro, thanks for advising. I have some TFSI bits here left over from my rebuild, if you need some stuff let me know and I will see what I have. I could maybe Pudo it to you as I'm guessing you aren't in the Eastern Cape?

[marlboro]

Cool @marlboro, thanks for advising. I have some TFSI bits here left over from my rebuild, if you need some stuff let me know and I will see what I have. I could maybe Pudo it to you as I'm guessing you aren't in the Eastern Cape?

Thanks for the offer! I’ll definitely consider it. Yes, you a bit far. I’m in Joburg.

[PhireSideZA]

Thanks for the offer! I’ll definitely consider it. Yes, you a bit far. I’m in Joburg.

Cool. Yeah, I have amassed a lot of parts in the last 1.5 years from playing parts darts with my TFSI. It eventually had to be completely rebuilt, as it was using a lot of oil and fuel, R40k later the oil consumption is better but it's still heavy on fuel - if I'm lucky, I will get 450km on a tank with 50/50 town/highway driving. If I don't find the cause of the horrific fuel consumption soon I will have to get rid of the car, which I'm hoping won't happen as the motor and a lot of the other bits are brand new.

Please keep us posted here with your progress. I'm holding thumbs that you only have the timing chain and tensioner to replace and that your valves have been saved.

[vce1232000]

Cool. Yeah, I have amassed a lot of parts in the last 1.5 years from playing parts darts with my TFSI. It eventually had to be completely rebuilt, as it was using a lot of oil and fuel, R40k later the oil consumption is better but it's still heavy on fuel - if I'm lucky, I will get 450km on a tank with 50/50 town/highway driving. If I don't find the cause of the horrific fuel consumption soon I will have to get rid of the car, which I'm hoping won't happen as the motor and a lot of the other bits are brand new.

Please keep us posted here with your progress. I'm holding thumbs that you only have the timing chain and tensioner to replace and that your valves have been saved.

check your mass air flow sensor & O2 sensor duty cycle with vcds

[PhireSideZA]

@vce1232000 - I am battling to quote your post - we have a dual transit outage from Africa to the rest of the world as WACS and SAT-3 is down due to a fault near the DRC so the site is loading slow here (dialup would be an improvement) - but I did update a thread I started last year with the latest info as to not derail @marlboro's thread further.

https://www.audizine.com/forum/showt...0#post14976280

[Theiceman]

agree... I also remove the vacuum pump 1st. This makes it easier to get to the screws

yup HPFP, vacuum pump, timing cover ..and if it's savable.. do the coolant flange while it's all off..

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[marlboro]

yup HPFP, vacuum pump, timing cover ..and if it's savable.. do the coolant flange while it's all off..

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I have replaced already the coolant flange about 50k km ago with an OEM part. No signs of leakage there. I don't think, I will need to replace it again.


So, I opened it up and it is indeed the cam chain. A piece of the tensioner broke off and the chain snapped. What is the easiest way to find out if I have bent valves without removing the head?

[vce1232000]

I have replaced already the coolant flange about 50k km ago with an OEM part. No signs of leakage there. I don't think, I will need to replace it again.


So, I opened it up and it is indeed the cam chain. A piece of the tensioner broke off and the chain snapped. What is the easiest way to find out if I have bent valves without removing the head?

Id remove the intake manifold & just look down into the intake ports. Or install the new chain & do a compression check

[marlboro]

Id remove the intake manifold & just look down into the intake ports. Or install the new chain & do a compression check

How am I going to be able to see if I remove the intake manifold and look into the ports? Don't I have to replace the chain and tensioner first, set the timing and start turning the engine to close each cylinder valves, shine a light though the spark plugs and see, if there is a gap? Or is it going to be visible, if I remove the intake manifold as it is?

[Theiceman]

my mechanic told me a quick redneck way to check ( no offense to red necks )

see my " that's all she wrote" thread. basically get each cylinder to TDC and pressurize it with air ( lock the crank with a wrench). use a rubber tipped air supply. when you remove the air it will blast out if you have compression. if nothing .. you are a leakin'
I attached a YouTube link in that thread..
of course it's not 100% fool proof but worked for me and I didn't have to remove the head

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[marlboro]

my mechanic told me a quick redneck way to check ( no offense to red necks )

see my " that's all she wrote" thread. basically get each cylinder to TDC and pressurize it with air ( lock the crank with a wrench). use a rubber tipped air supply. when you remove the air it will blast out if you have compression. if nothing .. you are a leakin'
I attached a YouTube link in that thread..
of course it's not 100% fool proof but worked for me and I didn't have to remove the head

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I saw that in your thread but I don't have a compressor. Is there a way to do something similar without compressor?

I also saw a reference of grinding a T55 torx in order to make the special tool but can't find exactly how I have to grind the torx. Can you point me to some pictures or a video? I have a Dremel, so I should be able to do it.

[Theiceman]

Get the right tools or leave the project to somone else .
thats all i can really offer.. even with the right tools it's easy to strip that bolt.

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[vce1232000]

How am I going to be able to see if I remove the intake manifold and look into the ports? Don't I have to replace the chain and tensioner first, set the timing and start turning the engine to close each cylinder valves, shine a light though the spark plugs and see, if there is a gap? Or is it going to be visible, if I remove the intake manifold as it is?

use a flashlight to shine down the intake ports. most of the time you be able to see the valve heads off center if they are bent from my experience. always can use a borescope to inspect also

- - - Updated - - -

Get the right tools or leave the project to somone else .
thats all i can really offer.. even with the right tools it's easy to strip that bolt.

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this is true..... Bust that bolt & your pretty screwed ....

[PhireSideZA]

@marlboro not sure what area you are in but Force Tools in Boksburg sells the M10 Ribe bit (PolyDrive) for R100 or so, you will need to however grind it down shorter to fit between the firewall and the head. The other option is pulling the cams and taking the cam to an engineering shop and have them remove it.

[marlboro]

@marlboro not sure what area you are in but Force Tools in Boksburg sells the M10 Ribe bit (PolyDrive) for R100 or so, you will need to however grind it down shorter to fit between the firewall and the head. The other option is pulling the cams and taking the cam to an engineering shop and have them remove it.

Thank for the tip about Force Tools. I'm a bit far from them but I can see if can go there or order it online. For that price is definitely worth getting the right tool.

Well, if the bolt strips, isn't the other option to remove the can cradle and, take the intake cam out and fit a new chain that way. I won't have to touch the exhaust cam at all in that case... unless there are bent valves and the whole head has to come out.

[PhireSideZA]

Thank for the tip about Force Tools. I'm a bit far from them but I can see if can go there or order it online. For that price is definitely worth getting the right tool.

Well, if the bolt strips, isn't the other option to remove the can cradle and, take the intake cam out and fit a new chain that way. I won't have to touch the exhaust cam at all in that case... unless there are bent valves and the whole head has to come out.

I did the whole 'girdle off' thing this weekend. We didn't find a good way to fit the chain with the exhaust cam in place, so both were removed as even with the tensioner retracted there isn't enough room to get the chain off the intake cam sprocket, and you can't get the tensioner off without removing the phaser, which, if your PolyDrive is stripped, means the whole cam is coming out anyway. The bolt is R50 from Goldwagen, and an engineering shop should be able to remove the old one for a few hundred rand.

Just be sure to mark the belt before removal and you should be okay. The bolts holding the girdle on are supposed to be torque to yield, but we reused mine. The bolt securing the cam pulley to the exhaust cam is also a one-time use part according to the manual. Also remember to get sealant to attach the girdle, and set aside an hour or so to clean the channels on the girdle as it's a major PITA to remove all the old sealant.

[Jayz691]

If the chain snapped, 95% chance ya got bent valves(intake). Either remove intake and inspect, or throw a chain and tensioner on, and check comp.
Far as tools, get the correct polydrive bit. Either the Audi, Assenmacher, or Schwaben(best imo). If the bolt strips, remove cradle and drill the head off the bolt. But id def replace the bolt on mayyer what, makes things much easier. And in case you gotta do it again...
Also, the newer genuine bokts seem to be revised, to fit the bits better. Last one I did, they bit snapped into place(zero play).

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