Mk 4 GT TDI 115 power loss and engine shake

[Pigdog]

Hi

I've just come to diesels from a VR6 and I'm not too sure what I should be expecting with the drive. The turbo kicks in at about 1800rpm and all is great, it really moves! But then at just under 3000rpm the power drops off with such force it feels like I've taken my foot off the accelerator, and that's it for the rest of the rev range, it just very slowly builds up. Is it normal for the power band to be this narrow? I've looked at a chip remap from angel tuning and they say it'll increase the bhp and powerband width. Anyone got any experience of them or just re-mapping benefits in general?

I've also heard talk of MAFs in relation to this but I'm not totally sure what they are and if they could be a cause of the problem?

Also when the car's cold and I'm freewheeling up to a stop, the engine judders until I actually do stop. This normal?

Any advice much appreciated!

Cheers

[Eshrules]

Hey, im not sure i can help with the engine shudder, but as for the lack of power, that sounds exactly like how mine was 2 days after i picked it up from the dealer!! turned out to be the turbo at fault, most people would take it off, have a look, clean the fins and see if that rectifies the problem, there has been mention of the EGR valve or the actual fins of the turbo sticking? so could be that. there is a chance it could be your MAF, although if it was your maf, i would have thought the lack of power would be felt across the entire rev range. the thing about it 'cutting' out at 3000rpm suggests that it is the turbo at fault. after hours of researching and trawling the forums, id probably have a go with the turbo first, dont replace it unless you have to i suppose, you cant really do much more harm having a go at cleaning it and making sure it doesnt stick. if all else fails, you're looking at around 200/400 for a recon/new turbo part. hope this helps!

[adamss24]

Check the turbocharger control valve(charge control solenoid) as the vanes may be sticky and the ecu detects the over boost and puts the engine in limp mode to protect it ! I believe that when you turn ignition off, it will run ok until the same overboost appears ! Failling that, there may be a boost leak somewhere and if you have the car scanned for fault codes i might be able to help a bit more !