Losing Turbo pressure @ 4500 rpm 4th gear

[eheijman]

Hi all,

I have a problem with my s3:

When I speed up to 4th gear and reach about 4500 rpm's I lose all turbo pressure. I have to wait a while before it picks up again. Last week the dealership replaced a "airmass sensor", which did not help much. It seems now that it happens when shifting from 4th to 5th gear. I still have to try it again to see when it exactly happens.

Have any of you experienced the same? Or heared about this?
One thing I could find is that I can be caused by a faulty wastegate.

Hope to hear back soon,

Thanks,
Eric

[JohnW]

Sounds to me like it might be producing overboost and going into limp mode.

I'd suggest you get it plugged into vag-com, or take it to the dealers and ask them to run the diagnostics.

Has it been chipped or tuned ?

Cheers,
John.

[wazza]

Possibly a DV problem, by the sound of it.
Get it checked out and don't try to recreate the situation often as you may be putting more stress on the turbo.

Welcome to RS246, and I hope you get it fixed soon. [img]images/graemlins/thumbs.gif[/img]
Nothing worse than a performance car that is performing poorly [img]images/graemlins/spineyes.gif[/img]

[bjacks]

Is it ok in the other gears? The ECU controls boost according to many things, including gears. Eg boost may be limited in 1st/2nd to help with slip/spin etc.
VAG-COM or preferably a visit to a respected tuner with a rolling road may be best.

Good luck,

Ben

[eheijman]

Thanks for all responses,

In the 1st, 2nd and 3rd gear I haven't experienced it.
The car isn't chipped/tuned. I just have the car for 3 weeks.
Coming thurday I'll go to the dealers, I hope they have some experience with this problem.

I'll will let you know the outcome!

Thanks for the welcome.

Eric

[bjacks]

As you do not have the problem in the other gears then hopefully it can't be anything serious. Let us know what the dealer says.

Cheers

Ben

[Scatmans3]

airmass sensors are a pain, no matter the "S"!
I have had so many pressure leaks I could probably give lessons in fighting it! Check your DV first, and specially, the hoses connected to the intercoolers. Those tend to crack up if they get too dry, and start leaking... then you'd feel the loss of pressure specially from 3rd gear on, because it's when you're getting full boost, mainly when re-accelerating. If that doesn't solve it, check other pressure hoses, because it's definetly one of those three... (nowhere else to leak!).
Wastegates do not usually present problems, and if yours did, you'd feel it in any gear.
If you're handy and want to check intercooler hoses by yourself, elevate the front of your car with the lower protection removed, have a friend acelerate it to 6000rpm and release several times (needless to say in neutral, doh), while you are under the car... if there is a leak you'd feel it simply by placing your hand on the hose because the gust of wind is easily perceived.
Nothing found, lower the car, pop the hood and start squeezing pressure hoses as he accelerates and see if they inflate... if they don't, there ya go!
(acceleration for testing should be 4000->6000... 4000>6000...)

Best of luck!
Alexander

[eheijman]

Well I had finally time today to go to the dealer. They said that if it wasn't the Air mass sensor that it could be allot of things. They had to realy check the car from top to bottom. As I am not that technical with cars I made an appointment for next week. Stange though that it doesn't seems to happen everytime when I accelerate. It also seemed like the car didn't have as much 'power' as normal, but maybe I'm just freaking out cause I don't know what is going on with the car and think that every sound is something bad,,,

I'll keep you up to date

[eheijman]

Well it has been a long time. Finaly had the dealership checkout my S3. They found a molten relay somewhere (connected to the secondary air pump???). Strangly enough today when I put the pedal down in 2nd gear the EPC light turned on and the engine went into "idle mode". Had to switch off/on before I could drive again. I have been reading some posts regarding this, and it appears to be the MAF. Strangely enough that has been replaced not even a year ago...... Any suggestions/help?

Thanks,
Eric

[DuncS3]

Isnt this the same problem I have currently?

[eheijman]

Dealer has changed the battery (it was broken), this seems to have solved the problem..


Hope problems won't return!!!