2.7Bi-turbo problem after problem help needed
Discussion
Ok I've had my 1999 S4 2.7bi-turbo for 2 years now and every 12 months or so the "Y" pipe at the front of the engine gets blown off by excessive pressure. I've had the car into and Audi Main dealer who told me I needed new turbos!!!! £3000 please, so I though, sod off usual Audi rubbish. Found myself an independant who replaced the pipe and again another 12 months driving. Then a V-MAX and since then all manner of problems, car seemed to loose power. Replaced lambda? sensors. Car OK but turbos now whistle. Anyway put the car under a heavy right foot and the turbos shut down. Took to garage again told that my dump valves/Waste gates?? need replacing the car is Over boosting?? Mean while I take the car home from the garage to return again today but on my journey home "Y" pipe blows off again. So its now sat at a garage in manchester with me basically wondering what the hells wrong with it. What is over boosting? can it be turned down?, some people are saying the car must be chipped but i dont know I am clueless and need all this bollox putting into English. I do know when he put the car on the VAG? computer it came up with "pressure control exceeded" possible diagnosis split pipe. Some one please help I love the car and dont want it to die just yet!!!
Sounds like an odd one. I'd be inclined to give a VAG tuning company a call to get their diagnosis. I can highly reccomend AmD. They aren't the cheapest place around but they know their onions. They are on an industrial estate in Bicester IIRC. Long time since I went there now. www.amdtechnik.com
As for dump valve failure, I am not sure, but unless BOTH wastegates have siezed up or something then they tend to fail open (ie: dumping all the exhaust pressure to atmosphere). Sometimes the actuator springs get weak with age - This will cause power loss but not that dramatic. I am not sure if the wastegates are electronically controlled on the 2.7TT so it could be the case that it's an electronics fault.
As I said. Beyond me now, so best speak to a speacialist.
If you are in the North West and fancy someone who knows their stuff to have a look - try Motorsport Developments in Bispham - just round the corner from TVR. They are primarily a Cosworth specialist, but what Stu and Kenny don't know about turbocharging and ECU maps isn't worth knowing - they come very highly recommended.
Roop
Roop
As for dump valve failure, I am not sure, but unless BOTH wastegates have siezed up or something then they tend to fail open (ie: dumping all the exhaust pressure to atmosphere). Sometimes the actuator springs get weak with age - This will cause power loss but not that dramatic. I am not sure if the wastegates are electronically controlled on the 2.7TT so it could be the case that it's an electronics fault.
As I said. Beyond me now, so best speak to a speacialist.
If you are in the North West and fancy someone who knows their stuff to have a look - try Motorsport Developments in Bispham - just round the corner from TVR. They are primarily a Cosworth specialist, but what Stu and Kenny don't know about turbocharging and ECU maps isn't worth knowing - they come very highly recommended.
Roop
Roop
charlieboy said:
Ok I've had my 1999 S4 2.7bi-turbo for 2 years now and every 12 months or so the "Y" pipe at the front of the engine gets blown off by excessive pressure. I've had the car into and Audi Main dealer who told me I needed new turbos!!!! £3000 please, so I though, sod off usual Audi rubbish. Found myself an independant who replaced the pipe and again another 12 months driving. Then a V-MAX and since then all manner of problems, car seemed to loose power. Replaced lambda? sensors. Car OK but turbos now whistle. Anyway put the car under a heavy right foot and the turbos shut down. Took to garage again told that my dump valves/Waste gates?? need replacing the car is Over boosting?? Mean while I take the car home from the garage to return again today but on my journey home "Y" pipe blows off again. So its now sat at a garage in manchester with me basically wondering what the hells wrong with it. What is over boosting? can it be turned down?, some people are saying the car must be chipped but i dont know I am clueless and need all this bollox putting into English. I do know when he put the car on the VAG? computer it came up with "pressure control exceeded" possible diagnosis split pipe. Some one please help I love the car and dont want it to die just yet!!!
charlieboy, I'm in Cheshire and can have a look at your car if you like?
Also, you could have a look at the B5 S4 forum on www.rs246.com There is lots of info about the car in there and plenty of people who will help you with the issues you're experiencing.
David
Also, you could have a look at the B5 S4 forum on www.rs246.com There is lots of info about the car in there and plenty of people who will help you with the issues you're experiencing.
David
Sounds as if you may have a boost leak. The stock hoses are know to leak. The fault code you have suggests this.
The F hose and the throttle body hose. Look for any oil around the hose.
There is a good mod available to prevent the failure of the rubber boot on the throttle body. Made by APR top bit of kit.
The F hose and the throttle body hose. Look for any oil around the hose.
There is a good mod available to prevent the failure of the rubber boot on the throttle body. Made by APR top bit of kit.
Dump vavles / wastegates are not the same thing are they?
They are known to split the diaphrams on the recirc "dump valves". Its well worth replacing the 710A's with the better 710N's and its only about £50.
Another vote for RS246.com, its a wealth of info - Only had mine for 2 weeks so far & am about to replace MAF, dump valves and check other boost hoses to prevent any probs.
When you say the turbos shut down - do you mean stalling? in which case I would suspect dodgy recirc valves
Daz
They are known to split the diaphrams on the recirc "dump valves". Its well worth replacing the 710A's with the better 710N's and its only about £50.
Another vote for RS246.com, its a wealth of info - Only had mine for 2 weeks so far & am about to replace MAF, dump valves and check other boost hoses to prevent any probs.
When you say the turbos shut down - do you mean stalling? in which case I would suspect dodgy recirc valves
Daz
In the medium to long term I would take your car to an independent specialist. If you can make the time, a trip to MRCTuning in Banbury would be you best bet.
In the short term I would take DavidT up on his offer. He knows his B5 S4s and I am sure has VAGCOM so can at least see what fault codes are being thrown up by your car.
(DavidT - we met at MRC a month or two ago. I had a black, standard S4 Avant having a health check)
In the short term I would take DavidT up on his offer. He knows his B5 S4s and I am sure has VAGCOM so can at least see what fault codes are being thrown up by your car.
(DavidT - we met at MRC a month or two ago. I had a black, standard S4 Avant having a health check)
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