vw sharan TDI - diesel running problems

Honest John Back Room » Technical matters
What is life like with your car? Let us know and win £500 in John Lewis vouchers | No thanks
View Threaded
Sun 30 Jan 2011 08:41
vw sharan TDI - diesel running problems - richbev

my sharan diesel is running badly. at low revs its fine but when i ask for full throttle the turbo comes in and out. i found a small hole in the waste gate vacume pipe and have since changed this. the waste gate linkage seems to move ok. its not seized. i have had a new air mass fitted and its been on the vag computer and didnt show any faults. the mechanic said could be the turbo but at the prices they are i need to be sure.

any help will be greatly appreciated.

Reply | Report as offensive | Link
Sun 30 Jan 2011 08:58
vw sharan TDI - diesel running problems - Peter.N.

Turbo's usually fail spectacularly, with lots of blue smoke from the exhaust, when you say its running badly do you mean rough or lack of power? You really need to take one pipe off so that you cam see or feel it its turning, could be remotely possible that something has got in and jammed it. Does it smoke at all?

Reply | Report as offensive | Link
Sun 30 Jan 2011 11:57
vw sharan TDI - diesel running problems - richbev

cheers pete.

the turbo is free. i can hear it. there is no smoke. the turbo kicks in and then cuts out. its like its over boosting and cutting the ignition. when i turn off the ignition the turbo comes back on. i found a small hole in a vacume pipe which went from the air box vacume pipe to the first solunoid/regulator. not sure what it is. it then goes to the waste gate solunoid. vw thought that the waste gate wasnt opening fully which was causing over boost and cutting the ignition. hence it comes back on when ignition is turned off then on.

Reply | Report as offensive | Link
Sun 30 Jan 2011 15:13
vw sharan TDI - diesel running problems - Peter.N.

Sounds like an electronic or sensor problem, could be to much boost pressure. Outside my experience I'm afraid, I have only recently got my first 'electronic' diesel.

Reply | Report as offensive | Link

From which small car to buy at which price point to the best UK-built cars, our Top 10s have the lot. Click now for your shortlist.

Unsure of what to buy? Our Top 10s are here to help you....