1.9 TDI Turbo problem, what to check next?

[John in Norway]

Hi,

my 2001 1.9 TDI Passat had an intermittent tubo problem, now the car is just a 'DI' because the turbo is not working at all...........

I took off the rubber inlet hose and checked that the impella spins freely........ it does spin freely.

Can someone help me out by telling me what things to check next, thanks in advance,

cheers,

-John (minus 1 C in the garage today!)

[Doctle Odd]

A scan might help as it could be the N75 valve has failed. Live data should tell you if the vanes are sticking. VCDS required!

[John in Norway]

A scan might help as it could be the N75 valve has failed. Live data should tell you if the vanes are sticking. VCDS required!

Thanks for the quick reply, I had my wife rev the engine a little and the lever on the turbocharger control unit is not moveing at all (is that bad?), might get to the workshop this week. If it get's above 5 degrees in the garage this week I might even have a look at it myself!

cheers,

-John

[philipharmes]

As soon as you start the engine the turbo control lever should pull in about 2cm.
If not, remove the vacuum pipe to the turbo & make sure there is vacuum from the pipe when the engine is running.

[John in Norway]

Hi phil, (and thanks)

when you say "the vacuum pipe to the turbo", do you mean the pipe that goes into the top of the wastegate control unit above th turbo? (just to make sure) I'l have a look tomorrow after work.

cheers,

-John

[philipharmes]

Hi phil, (and thanks)

when you say "the vacuum pipe to the turbo", do you mean the pipe that goes into the top of the wastegate control unit above th turbo? (just to make sure) I'l have a look tomorrow after work.

cheers,

-John

Yes, that's the one.
It doesn't actually have a wastegate.
The vacuum capsule controls the angle of the variable vanes on the exhaust side of the turbo, which controls the amount of boost from the turbo.
If you have no vacuum with the engine running, follow the small pipe back to the N75 valve & check if there is any vacuum there.

[John in Norway]

Yes, that's the one.
It doesn't actually have a wastegate.
The vacuum capsule controls the angle of the variable vanes on the exhaust side of the turbo, which controls the amount of boost from the turbo.
If you have no vacuum with the engine running, follow the small pipe back to the N75 valve & check if there is any vacuum there.

Thanks mate.........it's -1.5C in the garage this morning I migh wait until saturday afternoon when it's a bit warmer (above zero I hope)!

cheers,

-John

[John in Norway]

Hi,

just came in from th cold (-1C), cheked for suction at:

Turbo control unit hose
VNT actuator hose
Hose going into th top of the N75 & where that hose fits on the N75 (next to elecrical plug)

No suction anywhere........ what's next?

cheers & thanks for your help

-John

[philipharmes]

I hope Martin1810 doesn't mind me pushing his site.
Here is a diagram courtesy of Martin showing the ins & outs of the Passat vacuum setup.
B5 VACUUM HOSE DIAGRAM - PASSAT

[caldirun]

Check the vacuum hoses they rub through on the stupid plastic engine covers.