S4 performance issues

niall_wallace

Registered User
Hi, just new to this forum so go easy, have a 99 s4, had some fault codes which i resolved by reading previous posts etc, but one i am struggling to get rid of is

Turbocharger pressure control exceeded

I am aware these cars are common for boost leaks, or does this sound like a faulty N75 valve (i wasnt sure if these were bad for failing)

Any advice appreciated, cheers

Niall.
 

stapo69

All hail the mighty quattro!
had this, or similar a code, and it was a boost leak. A lower intercoler hose had split badly. Worth checking or your hoses 1st i'd say, especially the throttle body boot, where the 2 pressure pipes meet the intake manifold at the front of the engine under your centre cover, common fail point. Even better, if possible get your system pressure tested, at MRC, somewhere like that.
 

Dan Yeates

Audi S4 B5 Avant
Where are you? For £45 + VAT get it to MRC tuning. They will do a healthcheck and pressure test the turbo system. Well worth the money I think. They know what they're doing and get everything done so quickly.
 

andybnwc

Registered User
As above and dont put it off DO IT NOW!
 

aragorn

"Stick a V8 in it!"
Staff member
Moderator
VCDS Map User
just to clarify the above point.

Boost leak means the turbo has to work extra hard to produce the requested boost. Working extra hard means spinning faster, and if it overspeeds for any length of time, you'll kill the turbo.
 

niall_wallace

Registered User
thanks for the replies, yeah read up on these cars before i bought one, am driving very sedately until the car is running right, i am up in edinburgh, so mrc is a bit of a trek unfortunately.

thanks again

Niall.
 

aragorn

"Stick a V8 in it!"
Staff member
Moderator
VCDS Map User
ah cool, i'm up that way too.

You could pressure test it yourself? just need a big plug for the accordion hose and a compressor/airline...
 
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