My 2.0 TDI is going into limp mode and logging an overboost which can be temporarily overcome by turning off and on the iginition. Having read the threads I'm thinking stickey turbo vanes which seems to be pretty common with the BKD enegine and I've done 86k miles. Mechanic doesn't have time to look for a week but has suggested it might not necessary be the turbo as the air flow sensor and EGR could also cause the symtoms.

Here's the bit I'd appreciate any advice on:

1) Mechanic said to reset the overboost code and disconnect the air flow sensor to see if it goes into limp mode or if is OK. I did this and the performance was restricted and it logged a code for the senor saying low input. I'm not sure if this proved anything as with the sensor disconnected wouldn't go into limp mode anyway?

2) Next suggestion was that the EGR could be clogged up. Have not done anything with this but if it was clogged wouldn't it log it's own code and not show as an overboost or would show both.

Other suggestions were the obvious checking of hoses etc. The only other codes I can get on the car relate the glow plug cyclinder 3 circuit, not sure if this is related or just a glow plug on the way out

My wallet feels like it's going to get a beating!!!

It will be the turbo. The EGR and the MAF would log their own codes.

I'd agree. The key here is the comment about it being cleared on ignition reset. As the turbo isn't able to log faults or report on issues directly, as it's a mechanical device. Therefore on ignition reset the ECU will attempt to request the usual amount of boost from the turbo, and that's failing - hence limp mode. Reset the ignition and you get the chance to do the same again. And so on.

That's my take on it anyway. From what you've said and the circumstances you've provided.

Edited 23 February, 201115 yr by Wardy

Cheers guys - that's cleared things up for me, although obviously no one ever wants turbo issues!!!!

Wardy - I know your turbo went bang with style, did you get any limp mode indications or was it out of the blue?

Dougal

This one - no indications at all. Working fine and boosting correctly up until I tried to hold 3rd gear while getting upto NSL :S

I had one go on a Fabia previously, a few years ago. That let go a bit more gently - limp mode, checked the pipework over, usual boost pressure checks - then checked the turbo. Cracked vain on that one.

Hope you get your issue sorted. But until then, I wouldn't go using much performance at all, or requesting much boost.

Thanks Wardy - I'll be avoiding using the car as much as possible and driving like a nun!

Wow the third post on a failed 140tdi turbo in a couple of weeks, although at 86k you've done better than my 56k!

I got to 81k

I got to 115K

I got to 115K

no fair :'(

Mine went at only 11,500 miles :'( July 2005 car, turbo went a month after I bought it secondhand in Jan 2007, had same symptoms as yours, limp mode, turn off/on and it went away...

the turbo went quite spectacularly taking out the intercooler, engine and exhaust system as it sucked all the oil out of the sump and burnt it in a matter of seconds - HUGE cloud of smoke behind like when an old turbo era F1 car blew up... thanfully it was all replaced under warranty and has since done over 60k with no problems

Had to use the car today but drove like a nun..........never went above 2.5k revs and my fuel economy jumped up by 10mpg for the trip........pretty big difference but a real effort to drive without putting any load on the turbo

As others have said, it will be the turbo. Disconnecting the MAF produced the correct results, and the reset after an ignition cycle is classic :(

Had to use the car today but drove like a nun..........never went above 2.5k revs and my fuel economy jumped up by 10mpg for the trip........pretty big difference but a real effort to drive without putting any load on the turbo

I haven't gone above 2k for about 200 miles now, while my new one beds in! So I feel your pain :S

Is interesting to see how it is possible to keep up with traffic while completely off-boost. Does require a bit more effort though. Getting upto speed away from a junction is the real test mind you...

Get it looked at before it goes properly.

Garage confirmed today that the turbo needs replaced. Now I've got my next decision:

Option 1) Get a re-con turbo from Turbo Technics and get it fitted up here, the turbo would have a 1 year warranty but if anything did go wrong I would still have to cover the labour charges if I claimed under warranty.

Option 2) Garage would use a Skoda re-con unit and this would attract a 2 year warranty and if it went wrong the whole job would be covered for 2 years if anything went wrong.

The Turbo Technics turbo unit is £510 inc VAT and the Skoda one is £840 inc VAT. So a difference of £330!!!

Any opinions? I like the idea of total piece if mind for 2 years but the extra £330 would probably cover the labour if anything did happen to go wrong within two years.

Any opinions?

Dougall

Turbo Technics warranty on mine is 2yrs. Fair point about the ex-labour condition of the warranty. I noticed that as well.

Get the TT one fitted then a Warranty Direct warranty on the car with the difference? Least that way you'd have a year's warranty for the whole car, not just the turbo. Worth getting a price from them?

Just a thought...

Spoke with Turbo Technics again today, they confirmed that the re-man unit has a 2 year warranty so exactly the same as the Skoda re-man one (mis-heard that the first time).

So basically the difference is that the extra £330 would cover any labour/connected problems if anything goes wrong in 2 years.

My current thinking is to go with the Turbo Technics one and the £330 saving would cover the labour if the turbo did need to be changed out for any reason.

decisions decisions!!!!

Finally up and running again....got a reman Turbo from Turbo Technics and was fitted today..........hopefully that's the faint noise of a police siren gone and the over-boosts!

My Turbo on my 58 plate L&K LET GO AT 17000 MILES BEEN SORTED BY MONDAY BY A LOCAL TOP DEALER...and yes im Paso couldnt log in with my old login so renamed my self good to be back..