Overboosting problems

[Dean_W]

Evening All!!

The golf has been running sweet as a nut since the cambelt issue (see afew threads down). Now another one has reared it's ugly head. The dreaded overboost problem putting the car into limp mode by cutting the boost. This happened twice. Then I did a bit of digging.

I did some research and also spoke to the VW guys I use. We agreed it could be the N75 valve. A new replacement was sourced and fitted along with the other solenoid next to it. For 4 days the car has ran sweet. No overboost problems. Fuel consumption better than normal. Reduced soot. Bags of torque. I think the N75 may have been an underlying issue as the overboost is back with a vengeance.

Issues I am having are: -

Reduced fuel consumption
Turbo sounds like it's spooling to soon i.e. when cruising or when not requiring much torque
More soot
Lack of torque
Overboosting, so cutting the boost off

I'm along the lines of sticky vanes.......but the turbo has only done 30K at the most!

Stumped with this one lads. Any help appreciated. Cheers! Deano

[gazareth]

you need to check the boost pressure with a gauge before you go any further. make sure its within spec.

[sharki786]

I would also check for broken or split hoses. My mate had loads of soot and he "thought" his car had power till me and my mate drove it and there was no kick to it. So we opened the bonnet and revved it and saw oil being sprayed out. Turns out that his intercooler plastic pipe was crack. We replaced it and the clutch started to slip lol
The power was back.

[Dean_W]

Turns out that his intercooler plastic pipe was crack. We replaced it and the clutch started to slip lol
The power was back.

Definatley not a cracked intercooler pipe. Problem comes and goes. If it were a cracked pipe it would be there constant.