B8 A4 2.0 TFSI DIY: Carbon Intake Valve Cleaning

[Dcass08]

Oh they'll probly blame it on:
-american fuel
-driving style
-oil type
-tolerances
-gnomes

My money is on the Design Gnomes.

[Kafer_Mike]

I just did this about two hours ago. I was able to get a socket and 1/2" ratchet on the crank pulley bolt from above. If you do bump it with a starter for some reason, I'd add "remove fuel pump fuse" to the list of instructions. That and pull the connectors from the coil packs (I say this simply because I read it in the service manual. Not sure why they say to do it, but if it's in the book that's good enough reason for me.)

Cool. That is the only thing I wanted to confirm before starting. I didn't think to look before bolting on the belly pan after the timing belt swap. Thanks!

[eboosted]

Btw, have you already see any improvement in fuel mileage?

[Stuck'ite]

They clearly know about this problem. I'm sure they could care less since very few cars have it bad enough to actually cause a mechanical problem in the warranty period when they would actually have to do something about it.

The car uses virtually no oil between oil changes. So I'd assume what you see is probably typical for a B8 with similar mileage. Some will of course be slightly better and some slightly worse. People bitch about this problem a lot but really this took 5 hours and the car has 39,000 miles. It takes me just as long to rake my yard and I have to do that EVERY year. Of course if you're paying to have it done then you probably have something to bitch about. But then again maybe not because this is easy and anyone is capable of doing it if they have some minimal mechanical ability so there is a choice. No doubt though, if you had a V8 it would actually suck. Not sure I could have done this for 10 hours.

They do know about it. It is purely a function of being a TFSI motor (Direct Injection). The injector being in the combustion chamber means it does not spray fuel over the intake valves, which helps clean them. In all non-Direct Injection gas motors a typical BG Intake cleaning works because the fuel and BG Cleaner washed off the valves. It also takes around 100k+ to be needed because teh fuel washing over teh intake valves helps prevent this. TFSI motors are direct injection, so they need it every 40-50k. Audi has put a 5th injector in the intake manifold to test if it helps solve this problem. R8's need this service ever 15k or so (scary). I wonder if people with Catch Cans are seeing any improvement in this area. Audi people I talk to claim it is blow-by from the combustion chamber, not residue from the crank case ventilation, which would mean a Catch Can would have no effect. Audi also says the newer B8's (around 2011-on) have an oil separator built into the PCV System (I have a pic on my phone of one off the car I could post) that was suppose to help with this issue, and effectively eliminates the need for a catch can. . That said the crap people get out of their catch can is stunning.

[dscline]

Audi people I talk to claim it is blow-by from the combustion chamber, not residue from the crank case ventilation.... Audi also says the newer B8's (around 2011-on) have an oil separator built into the PCV System (I have a pic on my phone of one off the car I could post) that was suppose to help with this issue...

What Audi says doesn't jive with what Audi says.

[Hali Mark]

I attempted to replace my manifold on the weekend and got all the way to the last step before realizing I needed the M9 triple square bit. No stores had one so I had to put it all back together the next day. I'll have try to find one and give it another go later.

Has anyone replaced their manifold, or are you guys just doing the carbon cleaning and putting your own back on? I want to know what's involved in taking parts off the old manifold (throttle body, injectors, etc) and putting them on the new one. Is it simple or are there special tools or instructions required?

Thanks

[gnxuser]

I am actually really surprised to see this much carbon built up on the this motor... It is probably a good idea to do this but I bought a catch can to avoid this exact issue, however I have yet to see any oil in my catch can.

[Dan_Q]

Has anyone replaced their manifold, or are you guys just doing the carbon cleaning and putting your own back on? I want to know what's involved in taking parts off the old manifold (throttle body, injectors, etc) and putting them on the new one. Is it simple or are there special tools or instructions required?

I didn’t remove my fuel rail and throttle body but don’t recall it looking like much unique was required. Know it is recommended that you replace the o-rings on each injector but I didn’t do it and mine still fit very tight and I had no issues. That is one thing you may want to have on hand. If you are getting a full set of triple square bits and you have an assortment of socket swivels and extensions then I think you should be good. You may want to go to one of the online OEM parts sites and try to find the exploded diagram showing the throttle body and fuel rail installation to the manifold to make sure there aren’t any gaskets involved. It would be safe to have those on hand if you can’t find any better advice from someone who’s done it.

I am actually really surprised to see this much carbon built up on this motor.

Why do you think there would be less? The B7s had similar build up problems and our engine is nearly identical. For me this is about what I expected to see.

It is probably a good idea to do this but I bought a catch can to avoid this exact issue, however I have yet to see any oil in my catch can.

I haven’t seen anyone show any proof of their catch can working too well. Mostly we’ve seen a lot of water in them or else nothing in them. I’ve never actually seen a catch can work too well on any motor though I’m sure they help a little. A couple of folks installed them when their cars were nearly new. We need one of them to spend an hour to pull their manifold off after 20k miles to take a look. It wasn’t worth the ludicrous prices they fetch for me to bother with one. Esp since it is dubious if they’re doing much.

[Fburg A4]

There are a few special tools if you want to perform job correctly. One is T10133 to replace fuel injector teflon seals if injectors come out of head (or have dealer do this part). Another is adapting intake manjfold runner position sensor to the ECM if you remove/replace fuel rail. Old fuel rail would be swapped onto new manifold.
Most people are installing the old manifold after cleaning ports.

[gnxuser]

Why do you think there would be less? The B7s had similar build up problems and our engine is nearly identical. For me this is about what I expected to see.

I was secretly hoping that they might have magically fixed it

I haven’t seen anyone show any proof of their catch can working too well. Mostly we’ve seen a lot of water in them or else nothing in them. I’ve never actually seen a catch can work too well on any motor though I’m sure they help a little. A couple of folks installed them when their cars were nearly new. We need one of them to spend an hour to pull their manifold off after 20k miles to take a look. It wasn’t worth the ludicrous prices they fetch for me to bother with one. Esp since it is dubious if they’re doing much.

I think I had mine on since the car had 6K and now it's at 19K. I doubt that I will go through this cleaning process unless it starts to misfire or running poorly. My previous car with the BPY engine (MKV GTI) had 110K and I never bothered with the valve cleaning. The car ran fine, albeit it did burn some oil :-) However, the catch can on that one did have a bit of oil in it.

[Highlander1010]

Thanks Dan! Great write-up. I think this is something I'll do when Integrated Engineering comes out with their new intake manifold later this year (fingers crossed).

[van462]

I used this writeup and cleaned my intake valves today. My car had a M10 triple square bolt securing the intake manifold strut. Really great writeup, lead me right thru it. Another tip, I held a vacuum cleaner on the intake ports while i scraped off the big chunks before going in and cleaning with solvent.

[MilesM]

Commenting so I can find this later to follow. Thanks for the write up Dan!

[slvrb7]

He is correct about removing hpfp fuse and letting car die to help close valves and keep from having an issue also I believe you parking brake issue is that you have hill assist enabled and can disable via vagcom.

[Dan_Q]

I had to pull my manifold to replace the fuel rail pressure sensor and figured I'd take pics of what the valves look like 9,000 miles after the cleaning. Doesn't look too bad. Guess I'll probably plan to do this every 30-40k miles in the future. Having to do it again reminded me of a couple of things. One thing is just how easy this task is. Removing the manifold took me 28 minutes. The other one is that there are multiple fasteners that will be a PITA to locate of you drop them (I dropped two) adding about 20 min to the work. I recommend that you get one of those magnet on a stick tools if you don't already have one before starting this repair. Fortunately I have one and that is what I was able to fish them out with. If you drop a fastener and don't have a means of retrieving it then you'll be bumming.

Clean


9000 miles later


Clean


9000 miles later

[ddun]

Why'd you have to replace the sensor? I had some misfiring this past weekend, misfire frequency only happened once, but I also got fuel rail pressure too high with a frequency of 5.

This was at the beginning of a 100mile trip, and according to vcds it didn't repeat.

[yma4]

Great write up Dan! I definitely need to do this to my car but am hesitant that I would mess something up (not as "mechanically inclined" as you )

[Dan_Q]

Why'd you have to replace the sensor? I had some misfiring this past weekend, misfire frequency only happened once, but I also got fuel rail pressure too high with a frequency of 5.

This was at the beginning of a 100mile trip, and according to vcds it didn't repeat.

I have been getting an intermittent CEL (P0088 Fuel Rail Pressure Too High) for the last 6 months. Started out once every 6 weeks but has been increasing in frequency until it is now 1-2 times/week. I will put up a new post in about 2 weeks if it doesn't come back so I can confirm the sensor was indeed the problem.

[Rossagge]

Great write up! Gonna tackle this soon :)

[DoItAllGarage]

Nice DIY! I had to rate this thread 5 stars!

[wabbit23]

Dan,
Seeing that the buildup on the flaps pretty much melted off after you left them in the BG ISC for a while couldn't you just pour some onto the valves and leave it for a few hours. Maybe come back and reapply some to the shaft part but wouldn't that just melt off too?

I'm gonna be doing this in the next week or two since I still can't figure out why my cars not running at full potential even with new plugs, turbo and R8 Coils. Thanks for the write up in advance seems pretty easy to do.


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[Dan_Q]

Dan,
Seeing that the buildup on the flaps pretty much melted off after you left them in the BG ISC for a while couldn't you just pour some onto the valves and leave it for a few hours. Maybe come back and reapply some to the shaft part but wouldn't that just melt off too?

The valves get much hotter than the tumble flaps, so there was a way more baked on consistency to the buildup on them. So it may not work but give it a try and let us know how it goes!

[wabbit23]

I've got the BG Cleaner on order. It should be here by the 24th. Im gonna try and leave it on for a few hours and see what it looks like.

About how much time do you think you let the flaps sit in the solution?


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[Dan_Q]

About how much time do you think you let the flaps sit in the solution?

Probably about 3.5 hrs.

[wabbit23]

All 8 Valves are just as gunked up as this one. The stuff is caked on their but mushy!




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[wabbit23]

Am I just supposed to pour the BG ISC into the valve chamber?


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[wabbit23]

Filled them up and going to let them sit for a while. Looks like I'm gonna at least have to replace my filter but if this stuff seeps into the cylinder chamber I might just do an oil change.

For those of you that had injectors fall out, did you replace the Orings or just pop them back in?


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[Dan_Q]

Am I just supposed to pour the BG ISC into the valve chamber?

Looks like I'm gonna at least have to replace my filter but if this stuff seeps into the cylinder chamber I might just do an oil change.

For those of you that had injectors fall out, did you replace the Orings or just pop them back in?

Hopefully you only poured the cleaner into the valves that were closed. A closed valve should hold it without leaking into the cylinder. If you pour the cleaner into an open valve you're going to have to spray compressed air in there until it all evaporates. You CANNOT turn the engine on with fluid in the cylinder or you run the risk of hydrolock.

Every time I've had my intake manifold off there were three cylinders with valves closed and one with them open.

No reason you need to do an oil change. Even if you get cleaner into the cylinder it shouldn't get past the rings. Just make sure you evaporate it all out of there if you suspect that you got some in there. Best practice is obviously to never get any in there in the first place though.

I have not replaced the injector O-rings and it has not caused an issue. But I am sure it is good practice to replace them if you can easily get a hold of them.

[wabbit23]

Cylinder 1 looked closed so I started scraping that one first. I realized afterwords that it was the open one. Way too much gunk on it to even be able to see? I'm sure some deposits may have got into the cylinder. Do you think It'll be alright? Last thing I need is a blown motor.

Yeah, I'm not gonna put everything back together until Monday/Tuesday so I time might dry up whatever gets in the others. I'm gonna let the first 3 soak overnight and see what comes out in the morning.

Oh yeah I meant to say I'm gonna replace the oil filter alone. The dealer really cranked it on there so I busted a hole into it to unscrew it! It was really on there. Luckily a local VW dealership has a special on GTI filters so I might just pick up a few.


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[wabbit23]

Would you happen to know the torque spec for the manifold bolts?

I stripped the threads on one of rhe internal threads so I'm taking the manifold back off tomorrow to tap it and place in a helicoil but don't want to have to do any others once I put it back together.


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[Dan_Q]

Would you happen to know the torque spec for the manifold bolts?

I stripped the threads on one of rhe internal threads so I'm taking the manifold back off tomorrow to tap it and place in a helicoil but don't want to have to do any others once I put it back together.

That blows. Unfortunately I don't have the torque spec's on those bolts (or any bolts on this car). The lack of a repair manual or access to basic knowledge like this is one of the many things that make me regret purchasing an Audi.

[wabbit23]

Well I had today off so I managed to take the manifold off, drill, tap and I start the new threads and everything is bolted back together. She's back to running like a champ.

One thing that did concern me was some carbon chunk deposits on the valves. When I did the valve cleaning I had every single one of my valves looking like this

When I opened her back up it wasn't too bad but cylinders 1 and 3 each had 1 to 2 carbon chunks already sitting on top of the valves. I picked them off pretty easily and blew them out but that was definitely surprising considering I cleaned my valve less than 500 miles ago AND I just seafoamed through the intake manifold 2 days ago (which did nothing by the looks of things).

Oh well, my cars back together and everything's tightened back up properly.


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[Highlander1010]

I have been getting an intermittent CEL (P0088 Fuel Rail Pressure Too High) for the last 6 months. Started out once every 6 weeks but has been increasing in frequency until it is now 1-2 times/week. I will put up a new post in about 2 weeks if it doesn't come back so I can confirm the sensor was indeed the problem.

Any updates on this Dan. I'm tackling the same issue and have replaced multiple parts, including the sensor and HPFP without results. What were your findings?

[Dan_Q]

Any updates on this Dan. I'm tackling the same issue and have replaced multiple parts, including the sensor and HPFP without results. What were your findings?

Oh man I would be pissed. The HPFP is a pricey part.

I swapped the sensor but kept getting the code at about the same frequency. Then basically it just began happening less frequently and now I haven't had it in about 2 months. My next course of action was to replace a brass fitting that exists between the rigid line coming from the HPFP and Fuel Rail. It looks like simply a fitting but it may actually be some kind of valve. Audi lists it as a fitting but this thread indicates it is a valve. I could never get confirmation from Audi and didn't have the part number so I never ordered one. The issue seemed to go away before I took any further action.

[Eddie-B8]

Can someone who already purchased the cleaner post a link to the website they got it from

[k9lovr]

Can someone who already purchased the cleaner post a link to the website they got it from

I got it from Ebay....

[holyShred24]

Great write up and thanks! I just found a weekend project for next week!


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[Eddie-B8]

I got it from Ebay....

I only found a 6 pack on ebay, is that wat u got?

[k9lovr]

No I bought two cans from a place in Georgia a seller named impart1731...looks like a parts selling company...they have individual cans for sale now

[wabbit23]

I found carb cleaner to work just as well. The BG cleaner was great and all but in the end I still had to use a pick to break off all the chunks.


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