17965 Charge Pressure control: positive Deviation fault code

monkeyboy1983

Registered User
hi guys new to this forum but i did a diagnostics test on my 2001 Audi A6 1.9tdi and it came with the above fault code, i have been told it is something to do with sticking turbo vanes or something like that. i have read that mr muscle can do the job but would this not like melt the aluminium around turbo area etc, please help........
 

monkeyboy1983

Registered User
Right guys took off the egr today and it is absolutely covered in oil I will attach pics of them can someone help please
 

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mrnice

Registered User
Hi, I have same year and engine with 180k on it, I had same fault code and gunk pictured. I cleaned out egr (with oven cleaner) and refitted and gave the Mr muscle turbo clean a go. It solved the prob temporarily but turbo went bang a year later anyhow so I replaced with re manufactured unit. I don't think the Mr muscle treatment is a long term solution, just buys you some time. Turbo replacement is fairly easy, best of luck
 

desertstorm

Moderator
Staff member
Moderator
VCDS Map User
That EGR valve is not coked up at all it looks pretty normal off a car that 13 years old. The problem you have could be the VNT mechanism sticking but it could also be due to other things such as the MAP sensor failing, I have diagnosed 2 of these in the last 6 months on friends cars. The sensor fails and puts out the maximum voltage all the time so the ECU thinks that car is making 2 bar of boost at idle. Easily spotted with VCDS looking at the measuring blocks.
Could also be a problem with the N75 valve.Again doing some diagnostics and logging boost specified against actual will tell you a lot about what is going on.
If it is the vanes on the turbo sticking the very best way to clean it is removal and stripping the turbo. Mr Muscle may work but it is usually a temporary fix.
If the turbo is seriously overboosting then it won't last long, the reason the car goes to limp mode is to try and protect the turbo.
Karl.
 

monkeyboy1983

Registered User
Thanks for replies guys. How easy is it to replace turbo and where would be best place to get decent but not too expensive turbo?
 

mrnice

Registered User
Depends where you are, I got my refurbed one from the turbo guy in Glasgow (£300ish I think), but I expect there'll be a similar place near enough where ever you are. Unless you're buying new that is.
Might be worth checking the other points desertstorm mentioned though before pulling the turbo off. Order a new turbo oil feed pipe too if you do get a new turbo as the existing one will likely twist when undoing the banjo bolt. I got a nice flexible braided one from darkside developments, no more expensive than standard item, cheers
 
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