Driving back last night and the car's power delivery was really strange....it would boost and car would pick up speed, and then it would boost a little big more (like extended turbo lag!) - like turbo slip!

 

I then had a problem when I slowed down, the idle speed dropped down to 300 to 500 rpm almost stalling, recovering to 800 but fluctuating around 800.

 

Engine sounds different too, and MPG has really gone down hill.

 

This is after a cambelt change, oil/fuel filter change etc at the weekend.  Car was fine for 100 miles before problem arose.

 

Disconnected MAF, then airbox completely.  Checked boost pipes for oil, but interesting I tried starting the car with the boost pipe disconnected near the manifold and it started and idled perfectly.

 

I suspect the turbo as I have also noticed a slight "squeak" sounded like a slight boost leak, but it was there when I had disconnected the boost pipe - same noise and tone.

 

It was extremely hard to start after I had dropped my son off this morning - the engine fired, but to only 500 rpm and as soon as I pressed on the accelerator the engine died.  Took numerous attempts to get it go.

 

No fault codes stored.  Only thing I need to check is the engine timing on vagcom, but if this was out I would have though the problem would have been instant not 100 miles later. 

 

Can a failing turbo cause a really bad idle/poor starting?

 

 

VRS - mods in sig, done 70,000 on this turbo.

Well you know what you have done at the weekend, cambelt and fuel filter,

so check from there before starting introducing new faults.

Well you know what you have done at the weekend, cambelt and fuel filter,

so check from there before starting introducing new faults.

 

True, just strange that it drove perfectly for 100 miles.  Will check cambelt timing etc and fuel filter to rule them out.

mine was rough as a dog when cold smoking engine sounded terrible turned out my cam had gave up also no fault codes

Timing?

I'm thinking timing. As to the delay between belt change and symptoms, maybe the belt was on right but has since skipped a tooth? Certainly, particularly with VCDS, it's cheaper and easier to check and fix than anything else, like a worn camshaft.

Timing is now spot on (0 to -0.6)

 

thinking worn cam, as there is a horrible noise from the camcover at around 1200 rpm which disappears after that and is not there at idle.

 

I now cannot start the engine unless I hold the key in to keep the start motor spinning the engine.  Otherwise it just spins to 500rpm, tries to catch then dies.

 

Engine runs better from 2000rpm!   When turbo is cutting in with boost.

Edited 11 March, 201412 yr by trebormint

Strongly suspect the cam is dying if the timing is perfect, whip off the camcover and have a good look, you say you changed the oil, what oil did you use?