Turbo not kicking in..

[CraigyDe]

Hi, hope you lot can help...

My turbo sometimes doesn't kick in. If I stop, turn off engine then it'll kick in as it should.

Any ideas?

Cheers.

[scarr89]

When it doesn't kick in does it just rev and not go very fast? If so that is limp mode. Means something is causing you to go into like a 'safe' mode, where the car is only just driveable. Turning on and off re sets this.

A common problem is sticky vanes, the mechanism inside the turbo gets clogged up with soot and grime and doesn't function properly. You'll need to get this looked at if it is the case.

[CraigyDe]

Yup, does as you say..

I'm getting a new sump put on it this week so will ask the mech to have a look.

cheers.

[scarr89]

Yup, does as you say..

I'm getting a new sump put on it this week so will ask the mech to have a look.

cheers.

Sump will have nothing to do with it. It isn't a quick job. Remove your EGR valve and give that a clean, may help.

If it is really bad then you need to remove the turbo 

[CraigyDe]

The sump has a seperate issue. The sump plug was  over tightend and it's leaking oil.

[EsSeX dAn]

the only way to 100% fix this is fit a brand new turbo or have your turbo stripped and cleaned. as a quick fix you can use mr muscle oven cleaner up the hot side of the turbo and work the actuator

[Dean_W]

I had this problem a while back. Turned out I had a split boost hose. This caused the car to go into limp mode. Have a scout about and check all the hoses and clips are in good order. If that all seems ok then could possibly be a dodgy N75 valve. If that fails then as Dan suggested, could be the turbo unit. 

[Luke1981]

Just experienced this also on my TDI also (PD150). I lost boost at 80 mph on the motorway.  I could still manage to maintain the speed. Am I correct in thinking limp mode won't let you go past 55 mph ish?
If so, then I don't understand how I can still get 80 mph.
I also turned the engine off and on and it corrected itself and the boost was back. Any ideas?

Cheers

[scarr89]

Just experienced this also on my TDI also (PD150). I lost boost at 80 mph on the motorway.  I could still manage to maintain the speed. Am I correct in thinking limp mode won't let you go past 55 mph ish?
If so, then I don't understand how I can still get 80 mph.
I also turned the engine off and on and it corrected itself and the boost was back. Any ideas?

Cheers

That will be limp mode. Limp mode will basically stop your turbo from working. So you could make it to get 80mph maybe, I've never managed that fast!

Your turbo is probably gunked up if you are hitting limp mode. You get LM where the 'overboosts' (asks for too much boost) for a set period of time I think. So if you accelerate hard for like 10 secs you'll find you'll hit it rather than accelerating slowly for 20 seconds say...

[Dean_W]

Si, limp mode also works with underboost too.

Hence my previous post suggesting looking at the hoses etc.