Hi all.

My 04 VRS has developed a bizarre issue. When accellerating gently I can feel the car surging. If I look at the boost gauge I can see the needle going up and down quite a considerable distance. The car seems to surge or lurch about every second... Is this the surging thats usually associated with a failed/ing N75? I havent had any 'limp home mode' issues or any error lights and its only recently started. If i give full throttle, then it acts as I would expect, Up to full boost then slowly dropping off as the revs increase...

I have a generic Revo re-map, a CAI, and a Forge Splittr valve.

A friend has access to Vag-Com but he hasnt got round to doing a code check yet, Im presuming that would be my first port of call??

What would be the concensus here? Any help greatly appreciated..

Rob

Boost pipe leak would get my guess. A small leak forces the turbo to spool up harder and then slower, overshooting and undershooting aimed for boost.

Go over all the pipe connections, looking for oil leaks (from the oil vapour in the airflow), loose clips, etc.

HTH

Bas

Hi Bas,

Thanks for that. Im planning on doing a valet type thing today so will take a look at that first...

Cheers

Rob

What pressures are you seeing at the gauge on full throttle?

Also there is a pipe under the inlet manifold which can split and cause your problems, you should hear a hissing towards the top of the dip stick area.

Hi,

I see a peak of about 1.3 bar which drops very quickly to about 1 bar, then obviously tailing off as the engine speed increases...

Ill check that pipe aswell later on...

Rob