Another limpy turbo..

[philameena]

Seem to have the old turbo problemo.. but wondered if the specifics might pin down the issue or whether its still a mechanic job to pinpoint it.


54 plate Leon TDi 110.
41K on the clock.

Up to 18 months ago, lots of motorway driving. Avg about 12K a year.

Past 18 months. Mainly a couple of miles a day city driving. Very rarely get her above 35MPH


So.. Wednesday night.. first motorway driving for a while. Gets to 70mph then tries to accelerate and practically nothing there. Later on, listened out the window. No turbo whistle. No turbo.

Yesterday.. back to the commute. Turbo back in action again. Didn't push her.. but it was back when needed.

This morning. Cold start. Turbo still there, but I'm noticing that at the point it kicks in theres like a judder or wobble in the acceleration. The kind of feeling that at a very low speed would indicate a stall.


Apart from that, no problems. No dash lights or anything. Only thing out of the ordinary is a few drops of oil on the drive over the past couple of weeks (never ever dropped any oil before).
Last serviced in August. Oil still on the level. Regular dealer servicing since new.


So.. any ideas or still just anything from the:
MAF
N75
MAP SENSOR
STICKY VEINS
DODGY turbo

..list??

 

[UncleFester]

My guess would be coked up from stop start traffic and little or no hard driving which means lower exhaust temperatures which all means clogged up.

If it was mine, i'd check where the oil is coming from first and if it's not blowing out of the exhaust or turbo i'd take it for a good drive, get it warmed up first and use the gears / accelerator to make the turbo do something

 

[Muttley]

I'd suspect sticky VNT vanes in the turbo in the first instance too. More so if you haven't done anything to supress the EGR and/or fitted a catch can in the PCV system.

One possible way to get rid of the carbon build up is to get the turbo hot and keep it hot for as long as you can. That means loading the engine, keeping the revs in the mid-range. A long motorway hill is best for this, where you can keep it at around 70 or so. This is a more moderate (but legal) version of the "Italian Tune-up".

 

[philameena]

Sounds good.

But won't the turbo cut out and the engine go into limp mode if I try these ideas?

 

[UncleFester]

Sounds good.

But won't the turbo cut out and the engine go into limp mode if I try these ideas?

It will if you just plant your foot on the accelerator, you'll have to do this progressively to avoid limp mode

 

[sssstew]

yep they are right. To be sure you could spend a little time and drop the turbo off and give it a clean up and check its not sticking.

 

[glynnd]

This sounds more like an air mass meter fault than sticking vanes
Glynn

 

[dieselhead1]

Hi, are there any fault codes?

 

[glynnd]

You very rarely get fault codes with a failing maf.
Best bet is to buy a new one anyway. If the current one is a couple of years old or more then its a good starting point.
Glynn