Today whilst driving home from town (10 mile drive) my turbo suddenly stopped working at about 3000revs in 3rd, i proceeded to drive home but it didn't come back I stopped at the side of the road a mile away from home, turned off the engine removed the key and then restarted! all was fine turbo was back to normal! seems odd as it is perfectly fine now!

Any ideas of why this may have happened?

I have heard of ecu issues could this be it just playing up abit?

Cheers.

James.

Sounds like it went into limp mode.

Limp mode clears after you turn it off and re-start it.

It will have stored a fault code which will give you an idea of what caused it to go into limp mode - you'll need VAG-Com or a fault scanner to get the code, then you can look it up on here.

cheers, ill try to get it onto a diagnostics tool at the local garage hopefully!!

That'll cost you £50. :(

Worth investing in a handheld scanner, or see if anyone with VAGCOM on here lives near you and ask them, to get the code(s). It might point to a specific problem, or if not, at least you've got some knowledge before a garage just says whatever

probably an overboost caused by sticking vanes in the turbo..... :-(

probably an overboost caused by sticking vanes in the turbo..... :-(

It's classic symptoms of that.

when you say sticking vanes in the turbo, what do you mean? sticky wastegate?

Thanks for the replies, much appreciated!

the turbo had variable vanes which are moved by means of a vacuum system. The idea is that at slower engine speeds, with less exhaust gasses the internal diameter is reduced increasing the flow of the exhaust gasses and thus keeping the turbo spinning for longer. However is the car is driven at slower rpms too much of the time these vanes can get stuck. This in turn causes an overboost, and the car goes into limp mode to protect itself.

There is a nice animation somewhere showing the VNT.

Here you go: VNT15-Turbo

Go out and give it the full beans in second or third and rev it to 4k a few times - roads and speeds permitting - it will help clear the crud out, then make sure you do it regularly, they seem to soot up and stick if you drive on the torque and dont rev them enough - mine did start to stick years ago as i drove at low revs through the gears but now I regularly rev it and it seems fine.

when you say sticking vanes in the turbo, what do you mean? sticky wastegate?

Thanks for the replies, much appreciated!

Almost. There is no wastegate on a VNT turbo- the vanes do the same job (and more) by controlling boost.

It might also be worth working the VNT mecahnism back and forth from below the car a few times.

It may not help, but it costs nothing.

It might also be worth working the VNT mecahnism back and forth from below the car a few times.

It may not help, but it costs nothing.

If you have thin arms then you can operate it manually from above - easier than taking the under tray off and crawling under the car.

This sounds very similiar to what mine has done this morning! except i havent turned it back on yet as was late for work!

and as you say above I normally drive not really revving it above 3/4k but did have a little spirited drive last night, so maybe thats moved some crud!

I will plug it in vag com tonight, but good excuse to rev a bit more lol

Awol, it's not that likely you've got the same problem. The one being discussed is specific to gently driven diesels with the variable geometry turbos.

Ah! problem with just searching and trying to browse on the sly at work! :-)

ah well seemed to drive ok when got in at lunch time! see what vag com says tonight!

Fault code P0234 'turbo charger overboost condition' is the what might come up for the sticking VNT. Mine did this, at first once or twice a week and finally once or twice a day. Eventually the engine management light would come on. Someone claimed they cured theirs by using an injector / turbo cleaner in the fuel, but the only sure way is to clean the vanes or replace the turbo.