i have just got a mk4 golf gttdi 110bhp on a 51plate and when im on the motoway when i get to about 70mph my turbo stops working and if i turn the key off and on again it works fine till i get to 80mph and so on because its getting worse now as its just done it setting off from the lights can anyone can help.

 

99% sure it's going into limp mode becuse the VNT mechanisim is sticking. You can free it out, but in the long run, it's turbo replacement. Run a diagnostic just to be sure, but I have seen this many times

John

John

 

Sounds like it might be sticking vanes in the turbo mate.

I think there was a similar thread to this the other day and there were a couple of solutions on there.

Check all the small vacuum hoses too for splits, fallen off etc. They are quite sensitive to split or fallen off hoses.

 

Small chance it could be a split boost pipe, it was on mine with the same symptoms.

But 90% it is the VVT

 

Take a look here http://uk-mkivs.net/forums/p/394072/...5.aspx#2692605