Golf Mk4 GTI 150 Sticking Revs

[littlecham]

I've read through the previous threads, and Im struggling to find an answer, so apologies if I've missed it somewhere! I recently bought a 2000 Golf Mk4 Gti (150 version). I've run a diagnostics check and found nothing wrong. The problem seems most noticeable in 4th and 5th, though I suspect it happens elsewhere, just imperceptibly. The engine revs quite happily to about 3000 rpm where it wavers/sticks before continuing on. It gets to about 36/3700 and wavers again, but then continues round as if nothing is wrong. The same happens in 5th, although Im not sure which revs. This seems to happen whether the engine is cold or warm, and can be consistently recreated by holding the car at 2000rpm and then going to wide open throttle and holding. The turbo sounds like it is spinning, although as I have no boost guage I dont know if it is making the right pressure. Any help would greatly appreciated!

[mluton]

It could be a failed Diverter valve which is common.

Does it pull ok to the redline in 1st 2nd & 3rd ?

Welcome to the forum

[littlecham]

Hi, and thanks! I just tried it, it seems to pull fine in first and second, but it did hesitate in third, just before 3000RPM once.

What is the diverter valve? And whereabouts is it?

Thanks again

[mluton]

Take off the engine cover and you will see one of these at the rear right .
http://i132.photobucket.com/albums/q8/Lutons/DSC00222.jpg

If it pulls okay up to 4th then i doubt it will be the valve, but im unsure. Mine is a picture of an uprated one, but it will look the same, but plastic.

Only an idea, search "failed Diverter valve" and "MAF" and see what crops up. Usually the 2 main causes of loss of power.

[harrysaimbhi]

Hi, did the diverter valve sort this? i have a similar problem....?