Sudden Power Loss Golf Mk 5 TDI sport 140

[George Knott]

I've recently experienced a sudden drop in power, usually when overtaking. I assumed this was because of a throttle body problem (advised by my friendly VW specialist) after the engine warning light came on. I installed a new throttle body and for a few days all seemed well.. in that the warning light stayed off.. but when overtaking recently the power drop occurred again. Switching the ignition off and restarting corrects the problem immediately.. but it's a wee bit disconcerting to have a doubt about the car's overtaking ability.
I'll check through the suggestions I've read so far in this forum and see what happens.. any further thoughts would be welcome.

[paulkennedy]

It sounds like a turbo boost valve putting the car into limp mode. vcds should tell you and its an easy fix

[George Knott]

Thanks for your reply, Paul. I don't have access to a VCDS so I'll arrange another visit to my VW specialist. In the meantime I'll have a look inside the inlet manifold.. the car's done 113,000 miles and I daresay there may be some build-up in there.

[clarkyhall]

Hi Have had this problem on my 2.0 tdi bkd engine told I need a new turbo but I didnt, YOU will get told this is over boost P17425 code or something like that, now main dealer or independent will tell you that the only cure is a new turbo this is rubbish , if you go to a company called INNOTEC they specialise in turbo clean kits about £40 , this is a lot cheaper than forking out £1500 plus for a new turbo , its a 5 piece diy cleaning kit to clean the turbo its going to be your variable vain sticking in your turbo, this will cure it takes about an hour or so to do, did mine and its been brilliant ever since so give it a go very common problem , I did loads of research as I really didnt want to by a new turbo, Clive Atthowe in Norwich Norfolk had a look at my car and mentioned about this , here is a site to do some research on go to www.honestjohn.co.uk in the forum search box type mk5 2.0 tdi turbo problems good luck let me know how you get on