Very annoying boost problem!

[Rob W8]

Hi,
Its kind of difficult to describle but the car is accelerating in waves up to about 5000rpm then it seems to be ok. You can actually feel it as well pulling and easing off. The turbo can be heard whistling on and off as it accelerates.It does it worse when it is cold.
I took it to Audi and they replaced the throttle sensor. This didnt really help to be honest.
I have since had it serviced and was told a plug was knackered. These have all been changed and I even got a new MAF sensor whilst it was there for good measure just in case.

It is still doing it and is driving me crazy. I want to get it remapped soon and know that this will only get worse.

Is there and easy test to check for low boost or a split pipe etc??? Someone mentioned the Lambda sensor at a garage but I just got 4 new tyres as well so dont really want to keep forking out cash especially after crimbo.

It has got a Hyperboost Diverter Valve if this helps or hinders at all.

Please help...

Hope you all had a good Holiday (Creep Creep!) /ubbthreads/images/graemlins/beerchug.gif

 

[AL_B]

Hi mate,

Sounds strange. I know you said you don't want to keep forking out, but, one thing that you could try is a new N75 (Wastegate Frequency Valve)...about £36 from www.vagparts.com. Just get a standard one for your car...don't mess about with the different versions that are available.

There is a way to check for boost leaks, if you have VAG-COM, by logging requested and actual boost. These readings should be within 100-200 mbar of each other.

In the Audi motronic manual that I have, it suggested checking for leaks with "leak detector spray". I got some of this from VAGparts. But it was a bit expensive for what it was, and it came from germany. The idea is, you have your engine running, and spray it on specific hoses one at a time, if the engine note / idle changes, then you probably have a boost leak.

I wonder Carb / Injection cleaner will do the same job.

AL

 

[imported_bmx]

has the car any induction mods? mine used to do a similar thing when i had a ttda fitted. so i took it off and that cured it

 

[Rob W8]

No air filter mods bmx. Had a new filter at service so that should be cool.

Thanks for the advice AL. I had a look at Vagparts website but couldnt see the exact part for my car. Can I get the one for the golf?

Cheers,

Rob

 

[AL_B]

Rob,

Their web site doesn't list everything I'm afraid. Ringing them is best bet. Email responses can be a bit slow too.

Cheers

AL

 

[starski4578]

Hey mate i have a Quatty turbo aswell and have suffered exactly the same problem as you. Very annoying as no one can put there finger on exactly what it is. First they changed the air mass meter, then the engine temp sensor then the fan sensor as it kept turning itself on and off constantly, also replaced the dump valve. The only problem i have with the running now is when its cold like you say up to about 5000rpm. This has been going on since i got the car 5 months ago! I have had it revo remapped tho and it dosent make it anyworse. Soon as the temp gauge gets to about 90 the problem seems to go away and it pulls like a train. I to have heard someone mention the lambada sensor so thats probably the next line im gona take. You also mentioned the plugs, thats something else i thought it could be but wasnt sure why it would just effect it during cold running, think its more likely to be a sensor. Let me know what you do to cure it and i'll do the same if i get it sorted soon. Good luck!! /ubbthreads/images/graemlins/froggie_red.gif

 

[Rob W8]

Will do starski. Cheers for the replies guys.

Rob