RS5 carbon cleaning DIY

[TontoLoidRS5]

Joining and adding to the discussion here, you want to clean the PCV valves or at least check them for excessive oil or if they close and open. I believe a PCV valve that is too open is the number one cause for carbon buildup. The exception being on the the stem of the valve due to oil dripping down through the valve guide seals.

The hose + housing comes off easily once you have undone the torx t30 screw. Just pull it straight out.

It stinks of oil. Soaked the inside with valve cleaner. Going to track how quickly I get more oil dirt collect there, and if it is too quick I'll replace the respective PCV valve. Easy job but expensive part. Also with the piece off, isn't the easiest way to test the PCV valve to simply to blow into it, from the direction of the crankcase it should open up. Blowing from the other side it should close more or less?

Depending on how well the PCV valve works, will decide whether an oil catch can is necessary.

[TontoLoidRS5]

Joining and adding to the discussion here, you want to clean the PCV valves or at least check them for excessive oil or if they close and open. I believe a PCV valve that is too open is the number one cause for carbon buildup. The exception being on the the stem of the valve due to oil dripping down through the valve guide seals.

The hose + housing comes off easily once you have undone the torx t30 screw. Just pull it straight out.

It stinks of oil. Soaked the inside with valve cleaner. Going to track how quickly I get more oil dirt collect there, and if it is too quick I'll replace the respective PCV valve. Easy job but expensive part. Also with the piece off, isn't the easiest way to test the PCV valve to simply to blow into it, from the direction of the crankcase it should open up. Blowing from the other side it should close more or less?

Depending on how well the PCV valve works, will decide whether an oil catch can is necessary.

Not a lot of oil /dirt came out after soaking. Blowing air from both sides air is coming through so I probably need to get a new part from Audi to compare!

I am burning a liter or so more of oil than what is normal according to the users manual. That is with mostly highway driving and not overly aggressive.

[Ape Factory]

From my recent experience, oil brand and weight also contributes to oil consumption. I chose to leave my PCV's alone due to their fragile nature but it's probably not a bad idea to, at the very least, give them a once over drain out the excess oil. I know the major air/oil separator is located inside the valve covers but not sure if they actually "wear out or not". I've yet to see what they look like up close and personal.

In addition to the PCV system and oil getting past the valve guide, volatiles also get baked on during valve overlap events.

If you order and test new PCV's vs. the old, let us know the results!

[TontoLoidRS5]

Will do. I will also try to put them back on. The only part that is possibly fragile is the connector to the crank case on the end of the hose. But it came off easily I think it will come back on easy as well. Not a lot of dirt in them so far that I can see!

It could also be that the part is simply bad from design and constantly too open meaning oil will get sucked in contributing to the build up. I am close to (pretty much trouble free) 120,000 kms or 75,000 miles.

If anyone else has tested their PCV valves greatly appreciated if you let me know if they properly close!

[SteveRS4]

I'm not sure if they close ok but i did clean mine with alcohol and some carb cleaner not much came out a little oil maybe but there back on and seem to be working fine. Didn't do them any harm !!

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[SteveRS4]

Thinking about it I'm sure i tried to blow through them and could not !! I might wrong as it was quite a few weeks back now !

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[TontoLoidRS5]

Thanks SteveRS4.

I guess the following are good news regarding the engine. Hose and housing as mentioned are easy to get off. On top of the housing there is a lid with a small hole in it. Inside the housing there is a diaphragm and a spring underneath. If there is a crack in the diaphragm there will be a hissing sound. If it is large enough it can be stopped by plugging it with your finger allegedly. The good news are you can get the lid off and put it back on using just a screwdriver in the gap between the lid and the rest of the housing. I did just that and found a small crack. In the diaphragm. Alternatively if you aren't able to unscrew the oil cap at idle it could mean something is wrong with the one of the PCV valves. I had to listen really closely to hear the hissing but slightly easier when the engine is colder.

Luckily https://www.rkxtech.com/products/rkx-4-2l-pcv-valve allows you to buy just the diaphragm. Although just to clarify as it says until 2011 RS5 I would like to verify with any owner of that year or 2010 that the housings as hoses on their model years are the following: 079103245L . The one in the picture is not the right one. I have asked for clarification.

[TontoLoidRS5]

http://audirevolution.net/forum/index.php?topic=3793.0 there it is.

http://www.ozaudi.com/forums/showthr...ve-service-kit one way to get it.


Ordered the MB kit as I can get it in Europe and that way I get the seals as well. Set me back 150 USD for two. New complete audi kits would have cost me 350-360 USD but maybe I will get a slightly better offer from Audi Germany.

[TontoLoidRS5]

http://audirevolution.net/forum/index.php?topic=3793.0 there it is.

http://www.ozaudi.com/forums/showthr...ve-service-kit one way to get it.


Ordered the MB kit as I can get it in Europe and that way I get the seals as well. Set me back 150 USD for two. New complete audi kits would have cost me 350-360 USD but maybe I will get a slightly better offer from Audi Germany.

Audi Germany charge USD 145 for each.

[Ape Factory]

Yeah I had that same confusion, glad for confirmation, but if I remember correctly in some form or another, you COULDN'T finish the assembly with the retainers oriented the way they have them in the FSM. It's been a few months so I can't recall exactly why, but I know I "left them how I found them" because the other way just didn't work.

I had my intake manifolds off today swapping injectors and I oriented the spacers as pictured in the FSM diagram above. There's a notch on the solid bottom portion which corresponds with a notch in the injector so I'm convinced this is the correct way to install them.

[Slobo7x]

Post some pictures if you can, it's pretty unusual that all three of our RS5's had them installed wrong. lol

[Darel]

Min'e an S5 for the record but that doesn't change anything.

[Ape Factory]

This is with the spacer installed correctly.


See how the notch in the gray metal part corresponds with the protruding plastic notch on the injector itself?

Old injectors. Initially, I think I may have turned them over just for installation purposes as there's more surface area on the flat portion and mated up with the appropriately sized socket. I'd then flip them around into the correct position. I replaced all eight last night and I used the same procedure but definitely had the spring portion pointing up when I reassembled everything.

[SteveRS4]

I had my intake manifolds off today swapping injectors and I oriented the spacers as pictured in the FSM diagram above. There's a notch on the solid bottom portion which corresponds with a notch in the injector so I'm convinced this is the correct way to install them.

That does surprise me, as mine were the other way up to same as yours ! I'm over in the U.K as far as i know they have never been touched so must be from the factory like that ??

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[SteveRS4]

Does look spot on that way round, do you think it will make any difference that there upside down as i copied the photos from your carbon clean video/ instructions .....so i blame you !! (joking)

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[Slobo7x]

I wonder if it makes much difference in how the lower manifold compresses on the injector, especially during high engine vibrations.

Ultimately I don't think it matters too much as the LIM port for the injector is completely a circular surface, and the "arch" on the metal bracket for the injector is also spaced evenly to accommodate the plastic lip on the fuel injector itself.

I guess whatever helps us sleep at night

[SteveRS4]

I wonder if it makes much difference in how the lower manifold compresses on the injector, especially during high engine vibrations.

Ultimately I don't think it matters too much as the LIM port for the injector is completely a circular surface, and the "arch" on the metal bracket for the injector is also spaced evenly to accommodate the plastic lip on the fuel injector itself.

I guess whatever helps us sleep at night

Yeah lets hope so ! What your saying makes sense the gap between the LIM and the injector will still be the same i guess no matter what way round it is as long as it sits ok. I agree if it makes us sleep better then that's good for me too !

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[Ape Factory]

I know when the injector is fully seated in the cylinder head bore, it's fully seated. It won't go down any further as it physically bottoms out. The bung for the top of the injector has some "throw" to it, fudge factor if you will, it could sit further in or out and still seal.

The torque spec for the LIM is like 9Nm if I remember correctly. Aka, not that much pressure. The Upper is two stage but the final torque stage is 11Nm.

One thing I thought about was the LIM and UIM bolts are the same material as others on the car, ie. stretch bolts. One torquing and they're done. But it's such a low torque threshold I can't imagine using new bolts would make any difference.

I did manage to get the UIM on and off without dropping any of the grommets/spacers this round. When putting the UIM back on, I made to sure to press each spacer fully into the grommet and they all held on there securely.

[Ape Factory]

One more important note! It is absolutely necessary to use a vacuum pump to retract the flaps when installing the LIM. They WILL get caught on the port dividers. I experimented a bit with one side and they got caught up on the divider when not retracting them by using vacuum.

[Overbias]

If you haven't already, check out this excellent post and link:

https://www.audizine.com/forum/showt...L-Engine-specs

re discussion earlier in this thread on air oil separators I was particularly interested to note In the linked document:

'The CFSA engine also had a crankcase ventilation system which captured blow-by gases for combustion. To minimise the oil contained in the blow-by gases, the gases passed through a labyrinth oil separator (in the cylinder head cover) and a three-stage cyclonic micro oil separator.'

[Ape Factory]

If you haven't already, check out this excellent post and link:

https://www.audizine.com/forum/showt...L-Engine-specs

re discussion earlier in this thread on air oil separators I was particularly interested to note In the linked document:

'The CFSA engine also had a crankcase ventilation system which captured blow-by gases for combustion. To minimise the oil contained in the blow-by gases, the gases passed through a labyrinth oil separator (in the cylinder head cover) and a three-stage cyclonic micro oil separator.'

Yep, they're small and located on the underside of the valve cover (internally). Not sure how effective they are or rather, I'm not sure it matters how effective they are due to the amount of oil that's apparently dripping down the valve stems. I guess every little bit helps.

I posted a link to that article over a year ago. There are a few technical errors in it but overall it's a nice look at the CFSA.

[Ape Factory]

Thanks SteveRS4.

I guess the following are good news regarding the engine. Hose and housing as mentioned are easy to get off. On top of the housing there is a lid with a small hole in it. Inside the housing there is a diaphragm and a spring underneath. If there is a crack in the diaphragm there will be a hissing sound. If it is large enough it can be stopped by plugging it with your finger allegedly. The good news are you can get the lid off and put it back on using just a screwdriver in the gap between the lid and the rest of the housing. I did just that and found a small crack. In the diaphragm. Alternatively if you aren't able to unscrew the oil cap at idle it could mean something is wrong with the one of the PCV valves. I had to listen really closely to hear the hissing but slightly easier when the engine is colder.

Luckily https://www.rkxtech.com/products/rkx-4-2l-pcv-valve allows you to buy just the diaphragm. Although just to clarify as it says until 2011 RS5 I would like to verify with any owner of that year or 2010 that the housings as hoses on their model years are the following: 079103245L . The one in the picture is not the right one. I have asked for clarification.

Just an FYI, those diaphragms do not work on the RS5. The company is, however, planning on making a replacement diaphragm but it's at least six months out.

[Overbias]

Yup, and back to your earlier point, there would be no way to intercept the breather path to insert a 3rd party air oil separator to externally remove the oil. Clearly the PCV's are not the entire recirculation route.

We discovered that the PCV's installed from factory were not (and never had been) associated with the VIN of my car. Nobody is quite sure how they ended up there but when the tech went to replace them they were not found in their parts system.

[Ape Factory]

Yup, and back to your earlier point, there would be no way to intercept the breather path to insert a 3rd party air oil separator to externally remove the oil. Clearly the PCV's are not the entire recirculation route.

We discovered that the PCV's installed from factory were not (and never had been) associated with the VIN of my car. Nobody is quite sure how they ended up there but when the tech went to replace them they were not found in their parts system.

You could intercept the airflow path primarily by taking it from the valve cover, through a new air/oil separator then on to the PCV's on either side. After examining my car post clean plus 10K miles, I'm convinced it's all flowing down past the valve guides for the most part. I'm going to do an experiment with the CRC valve/turbo cleaner and see if it makes a difference. I'll pull the upper intake manifold off and look after the procedure has been performed. Will post pics.

To look at long and short term fuel trim as well as misfires, with the VCDS launched, choose the control modules. From there choose "01 Engine" (not the transmission which is highlighted).


Once you're in the engine control module, select "Adv. Meas. Values". This is also where you can select any engine parameter to log live.


Once in Adv. Meas. Values, there's a window on the right. Just check the boxes/measuring values you want to record. You can click up to eight and still have "turbo" mode where the sample rate is high enough to make good logs. I've selected Misfires per 1000 revolutions for all eight cylinders. The engine is actually running during this screen shot and it's post-injector swap.


Here's fuel trim.

[Darel]

What practical information does knowing that fuel trim tell you? What numbers should we see there, and what would be a red flag?

[Ape Factory]

So basically your short term fuel trim will fluctuate quite rapidly as it's being adjusted in real time. If you're positive, that means the ECU is compensating for a slight lean condition. If you're negative, you're rich. Your long term trim will adapt and change over time. Mine is still changing after swapping in the new injectors. Generally, if you're seeing over 10% in either direction, there's an issue. I'm guessing but if you start seeing +/-20%, it'll most likely throw a code. Anything below 8-9% is probably pretty normal. Once I've run my car enough with the new injectors, I should be around 0 to 3% or thereabouts.

[SteveRS4]

So basically your short term fuel trim will fluctuate quite rapidly as it's being adjusted in real time. If you're positive, that means the ECU is compensating for a slight lean condition. If you're negative, you're rich. Your long term trim will adapt and change over time. Mine is still changing after swapping in the new injectors. Generally, if you're seeing over 10% in either direction, there's an issue. I'm guessing but if you start seeing +/-20%, it'll most likely throw a code. Anything below 8-9% is probably pretty normal. Once I've run my car enough with the new injectors, I should be around 0 to 3% or thereabouts.

Thanks Michel was going to ask what to look for on the fuel trim and how to bring it up on VCDS nice one
Will also be very interested in how you get on with the CRC valve/ turbo cleaner experiment keep us posted ! Be great if there's a way to keep the carbon build up down between carbon cleans.

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[Darel]

Great info, thanks! This thread should get stickied.

[Ape Factory]

Thanks Michel was going to ask what to look for on the fuel trim and how to bring it up on VCDS nice one
Will also be very interested in how you get on with the CRC valve/ turbo cleaner experiment keep us posted ! Be great if there's a way to keep the carbon build up down between carbon cleans.

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I may try to do that on Monday but I won't remove the intake for another week as I have some new upper/lower gaskets coming. Still, should be able to see a difference but it might not be where it's important, around the edge of the valve head and the valve seat. We shall see!

[SteveRS4]

I may try to do that on Monday but I won't remove the intake for another week as I have some new upper/lower gaskets coming. Still, should be able to see a difference but it might not be where it's important, around the edge of the valve head and the valve seat. We shall see!

Yes will be interesting to see ! Also if it reaches all the intake valves especially cylinders 1-4-5-8 as i dont know about yours but these had the most carbon build up on mine? Like i say keep us posted

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[Ape Factory]

I plan on injecting half a can on either throttle body side and yes, I did notice some had more carbon than others although I didn't take notes on which ones like I should have.

[SteveRS4]

Yeah i noted it and mine was 1-4-5-8 either end of the block as such, lets hope it does what we want it to do! Half a can on each side should be plenty ill keep my fingers crossed it works even if it takes some of it away we might be able to do a carbon clean less often that would be a result !

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[Yoda1]

I plan on injecting half a can on either throttle body side and yes, I did notice some had more carbon than others although I didn't take notes on which ones like I should have.

This is great! I’ll be in background looking/reading. I was not able to think of an more effective place to spray the carbon cleaner spray. Would be cool if there was a cleaner designed as an expanding foam and applied with engine off, that would make contact with all inside surface areas then dissolves the oil grime that’s built up over the 10k miles. Maybe a simple carb spray to wash that down afterwards with engine running.

[Ape Factory]

I used the CRC valve cleaner yesterday. Per their instructions, I warmed the car up. Drove it around for a bit until it was up to temp. Pulled into the driveway and took off both intake elbows. Had a helper maintain 2,000 rpm and I tried to keep the application even for both throttle bodies by counting in seconds. Ten seconds for one side, switch to the other and vice versa, until the can was empty.

Once you've emptied the can, the car needs to sit for an hour and you're then supposed to drive it on the highway for at least 10 minutes. They also say it continues to clean for the next 7 or 8 days. So I took it on the highway, drove for 35 minutes to the nearest drag strip and spent the day making runs. Despite a DA of over 2200 feet and ambient air temps around 75 degrees, I ran my best time. Still no records but that was encouraging given the conditions. Now it should be noted I just changed out all eight of my injectors and I believe that's where the difference came from.

I'll pull the upper intake manifold next weekend and have a look. And yes, I shot a video :) I should have the part 1 teaser up this week, maybe even today if I have time.

[SteveRS4]

I used the CRC valve cleaner yesterday. Per their instructions, I warmed the car up. Drove it around for a bit until it was up to temp. Pulled into the driveway and took off both intake elbows. Had a helper maintain 2,000 rpm and I tried to keep the application even for both throttle bodies by counting in seconds. Ten seconds for one side, switch to the other and vice versa, until the can was empty.

Once you've emptied the can, the car needs to sit for an hour and you're then supposed to drive it on the highway for at least 10 minutes. They also say it continues to clean for the next 7 or 8 days. So I took it on the highway, drove for 35 minutes to the nearest drag strip and spent the day making runs. Despite a DA of over 2200 feet and ambient air temps around 75 degrees, I ran my best time. Still no records but that was encouraging given the conditions. Now it should be noted I just changed out all eight of my injectors and I believe that's where the difference came from.

I'll pull the upper intake manifold next weekend and have a look. And yes, I shot a video :) I should have the part 1 teaser up this week, maybe even today if I have time.

That's great Michel will be interesting to see how the valves look and what the results are ! Your a star for doing a video thought you might ! Sounds as if you had a good day at the drag strip and really glad your times are getting better all the time !!!

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[Ape Factory]

So still working on the video and I should have it up within a day or two. Turning out to be more complicated than I thought and I'm trying to minimize "talking head" time. Yes, I'll actually be talking on camera for a change. I'll most likely post it up on the "other site" though as well as my YouTube channel.

PS-I actually give a mini-shout out to you Steve!

[SteveRS4]

So still working on the video and I should have it up within a day or two. Turning out to be more complicated than I thought and I'm trying to minimize "talking head" time. Yes, I'll actually be talking on camera for a change. I'll most likely post it up on the "other site" though as well as my YouTube channel.

PS-I actually give a mini-shout out to you Steve!

Wow !! That's great thanks Michel I'm famous haha ! Bloody hell your gonna be talking that's a first someone's getting brave in front of the camera !!! No really tho, that's great like I've said will be good if this works even to a degree ! It will be interesting to see what the results are and if this stuff really works or not ! Nice one Michel

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[SteveRS4]

So still working on the video and I should have it up within a day or two. Turning out to be more complicated than I thought and I'm trying to minimize "talking head" time. Yes, I'll actually be talking on camera for a change. I'll most likely post it up on the "other site" though as well as my YouTube channel.

PS-I actually give a mini-shout out to you Steve!

Hey Michel how you getting on with the video ? Also i know you probs can't say on here but what's the "other site" drop me an email cheers buddy

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[jschrauwen]

SteveRS4 - have you carbon cleaned your B7 RS4 yet?
I just acquired a 2008 R8 V8 and thought with so much similarities between them, I could get some insight into this process. My B8 A5 3.2L was quite easy to do as the fuel rails and injectors are not removed as part of the process.


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[SteveRS4]

SteveRS4 - have you carbon cleaned your B7 RS4 yet?
I just acquired a 2008 R8 V8 and thought with so much similarities between them, I could get some insight into this process. My B8 A5 3.2L was quite easy to do as the fuel rails and injectors are not removed as part of the process.


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Very nice love the R8 !! I'm afraid my RS4 is a B8 as i live in the U.K not a B7 so mine is the same engine as the RS5 B8's. I'm not sure of the differences that the B7 and B8 have to be honest as I've never looked into it that much maybe someone else will know on here and chime in, i wouldn't of thought there would be to many differences tho sorry i couldn't of been more help. Ape on here is very knowledgeable and has a video and a very detailed write up of the rs5 B8 on how to do a carbon clean might give you an idea of what your looking at ?

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