996TT Not making boost problem

[saulk]

My TT was running fine all day and yesterday evening it was quite cold (2 degrees)and was pulling well, then I noticed that when coming onto boost it would pull hard up to about 4k revs and then just completly drop all boost and behave like a normally aspirated car over the rest of the rev range. The boost gauge was only showing .5 bar and the car was definately holding well back. It was very misty and the air was really damp so i'm wondering if the moist air would stop the car making full boost and cause this problem or could it be a diverter valve? I haven't had the car out this mornig yet to test it nw the mist has lifted.

[klm]

Mine was the same last night untill the car was well warmed up.

[craigturbo2]

Sounds like you might have a leaking dump vavle,If it runs standerd ones i.e. Bosch they really require replacing after 10K,not expensive and easy to change £25.00 each.

Regards Craig

[t urbo]

If its under warranty then take it back. If you are going to replace the DV's yourself then your better off going for the EVO ones, they last longer and wont need to be changed if you upgrade.

[saulk]

cheers guys,

Car does seem better today but not 100%. I was thinking of changing DV's anyway to the Evo ones or the ones that AMD sell.

[kiko]

Check your MAF with a PST2 tester and check for boost leaks.