Audi A4 Avant - turbo over boosting

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Sat 9 Nov 2013 14:47
Audi A4 Avant - turbo over boosting - dave1574

Hi there i have had this problem with my audi for 4 weeks now it boosts up to 2000 revs and then just gos into a sort of limp mode it is reving but really go,s slow i have to stop the car and turn it off restart and all is good i have had it on a diagnostic machine and it is saying it is over boosting i have change the EGR valve but it is still happening can any body help ???

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Sat 9 Nov 2013 15:16
Audi A4 Avant - turbo over boosting - galileo

Could be stuck vanes on the turbo, unless you regularly use full rev range carbon can build up and the vanes stick. Also a possible fault with the actuator that moves the vanes.

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Sat 9 Nov 2013 15:37
Audi A4 Avant - turbo over boosting - dave1574

thank you for that i am reading about cleaning the vanes in the turbo with mr mr muscle cleaner they say it is great ??? do you no anybody that has tried this ??

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Sat 9 Nov 2013 19:16
Audi A4 Avant - turbo over boosting - galileo

thank you for that i am reading about cleaning the vanes in the turbo with mr mr muscle cleaner they say it is great ??? do you no anybody that has tried this ??

Can't say I have, the problem would be getting it into the right area, not sure what adverse side effects Mr Muscle might have on other parts of the turbo.

Dismantling to get full access to the vanes probably means disturbing the mounting of the actuator and its settings, so unless you know what you are doing and can ensure all is reset correctly I wouldn't recommend that.

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Sat 9 Nov 2013 19:52
Audi A4 Avant - turbo over boosting - elekie&a/c doctor

This is what you need;www.spmap.co.uk/index.php/products/workshop/revive...r

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Sun 10 Nov 2013 08:22
Audi A4 Avant - turbo over boosting - dave1574
Thank you I will get some revive turbo
Cleaner they don't sell it by me so I think
It's on line I go ... Thanks again
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Sun 10 Nov 2013 07:51
Audi A4 Avant - turbo over boosting - dave1574

thank you for that i am reading about cleaning the vanes in the turbo with mr mr muscle cleaner they say it is great ??? do you no anybody that has tried this ??

Can't say I have, the problem would be getting it into the right area, not sure what adverse side effects Mr Muscle might have on other parts of the turbo.

Dismantling to get full access to the vanes probably means disturbing the mounting of the actuator and its settings, so unless you know what you are doing and can ensure all is reset correctly I wouldn't recommend that.

ok thanks again
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Sun 10 Nov 2013 08:06
Audi A4 Avant - turbo over boosting - dave1574
Is there a good turbo cleaner out there ???
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Sun 10 Nov 2013 08:17
Audi A4 Avant - turbo over boosting - dave1574
Thanks for that I am going to get
some advent turbo cleaner and try it looks good stuff
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Sun 10 Nov 2013 08:19
Audi A4 Avant - turbo over boosting - dave1574
Thank you I am going to get some
Revive turbo cleaner it looks good stuff
Thanks again
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Sun 10 Nov 2013 17:15
Audi A4 Avant - turbo over boosting - The-Mechanic

Dave,

I have used Mr Muscle in my Seat Leon 1.9 TDI to great effect ie, it cured the sticking vanes totally. That Revive cleaner looks a good idea in theory, but I personally have doubts about it's effectiveness as reading into it, the cleaning solution is sprayed into the air intake which in turn gets burnt in the cylinders which then cleans off the carbon using the exhaust gasses to transfer it to the turbo yes ? Surely if this would dilute it's effect. I'm sure it would have some effect, but not as much as getting a solution directly into the problem area such as the Mr Muscle method for which I used this guide

www.audi-sport.net/vb/a4-s4-forum-b5-chassis/10712...l

sure, it takes a little longer but, if you heed the instructions, the results speak for themselves. I did mine 6 months ago and have not had an issue with either limp mode or any damage to the turbo.

Further reading on this forum

www.seatcupra.net/forums/showthread.php?t=350703

shows that the Revive product is more effective at dislodging light carbon deposits from the EGR valve/intake manifold than the actual turbo. One of it's developers contributed to the thread but I'm not convinced by some of his comments. Revive costs around £60ish, Mr Muscle around £4ish....... Personally, I'd go for the cheaper, proven option first.

Obviously you need to confirm that it's not the vacuum diaphragm or a pipe that's causing the fault first, then if necessary, un-stick the vanes as you see fit.

Edited by The-Mechanic on 10/11/2013 at 17:18

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Sun 10 Nov 2013 17:23
Audi A4 Avant - turbo over boosting - galileo

The firm I worked for made new turbos (heavy duty, not for cars) and also re-manufactured used ones. Most of these were very dirty when returned, I can well believe that spraying a cleaner into the intake will make the impeller and compressor air passages nice and clean.

However, I question the ability of a cleaning fluid to have much effect on stuck vanes in the turbine housing. It has been blown into the cylinders, compressed with air to 1000 degrees C and then heated further when the fuel is injected and burned, so what goes out of the exhaust manifold to the vanes is just hot gas, how is that going to clean things up?

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Sun 10 Nov 2013 22:07
Audi A4 Avant - turbo over boosting - The-Mechanic

Exactly my thoughts galileo,

At least with Mr Muscle it's sprayed directly into the turbo impeller housing where it foams up coating the vane mechanism and dissolves the carbon deposits. With a spray that has gone through the intake system, then is burnt in the cylinders with the fuel/air charge what use would it be ? Revive claims to dislodge carbon from the intake tract, surely if a piece of carbon gets through the intake manifold and into the cylinder(s), the result could be catastrophic.

Mr Muscle is sprayed inside the "hot" side of the turbo where, when it's done it's job, is blown out directly into the exhaust system so it never gets a chance to get rogue carbon deposits inside the combustion chambers.

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Tue 12 Nov 2013 17:02
Audi A4 Avant - turbo over boosting - slkfanboy

Another vote for Mr Muscle. No sure on the age of your car, but check all vacuum pipes and ensure the vanes move freely after cleaning

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Sun 10 Nov 2013 22:34
Audi A4 Avant - turbo over boosting - Big John

Not sure how old or what cc your Audi is.

However if it is the diesel PD version with solenoid vacuum valves to operate EGR, turbo variable vanes and antishudder then check you don't have a leak or that a solenoid has failed. A clue to a vacuum failure of some sort is that the anti shudder doesn't work (shudders on turn off).

Problems with the vacuum pipes are COMMON especially with the briaded rubber pipes but also vibrations can wear through the hard small bore pipes. The vacuum system starts with a T piece near the brake servo feeding a pipe running accross the bulkhead on route to the EGR valve solenoid. It the crosses back over to the other side for the solenoids that operate the EGR and anti shudder vlaves.

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Sun 10 Nov 2013 23:19
Audi A4 Avant - turbo over boosting - dave1574

thank you all for helping me i am a bit worried about useing oven cleaner on my 06 plate audi i am going to try the revive and see how i get on if no good oven cleaner it is thanks again

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