Boost problem with chipped 1.8t AEB

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Aug 6, 2009 | 05:50 PM

mathieums

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Audiworld Junior Member

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Boost problem with chipped 1.8t AEB

Hello guys,

I've got a weird problem with my car the other day while heading to montreal.

Since I bought the car 3 years ago, the car would always boost around 10-12 psi and peak around 14-16 psi.

But the other day the boost gauge indicated that I was peaking and keeping more than 20 psi on the stock k03 turbo.

So I took it easy because I didnt want to run lean. After a few kilometers I tried again to floor it and it was stock at 5 psi.

Right after, I try it again and then it was going nut. Jumping from 20 to 5, then to 10, back to 5 and right back to 20.

So I arrived at destination. I stop the car and do my things. After a few hours I try the car and it was back to normal.

Now everything is back to normal but it only boost between 8-10 psi and peak around 12.

What the hell is wrong?

DV? I don't think so.
N75? Very possible imo
Wastegate? Possible...

Anyone have an idea?

Thanks
Mat

Aug 8, 2009 | 06:29 PM

RallyVermont

Mr Mc Feely

Joined: Feb 2003

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Do you have access to a Vag Com? try to pull some codes. could be plenty of things.

Aug 8, 2009 | 11:38 PM

bmwbiker

AudiWorld Member

Joined: Aug 2009

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Did the car accel and run normal and did the check engine light come on ?,
If no check engine light and normal running I thinks you boost gage went
wacko. THe check engine light should have come on and the engine cut out if the boost went to 20 psi

Aug 9, 2009 | 12:51 PM

mathieums

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Audiworld Junior Member

Joined: May 2007

Posts: 30

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Quote:

Originally Posted by bmwbiker

No limp mode, no check engine light. I do have a vag-com but since I didnt had any CEL I didnt check.

My boost gage is correct. I heard more "pssssshhhhhhhhhhh" then I normaly do.

I really think the problem is the frequency valve (aka N75 valve).

The car was acting normaly until it hit 20 psi. At 20 psi it was very weird. But now that you're talking about it, it was kicking so I think I can conclude that it was the ecu cutting the fuel injectors.

Its been around 2 weeks since I had that problem. The car is back to normal but I have about 2-3 psi of boost less then before.