110BHP '99 Tdi trouble

**BoraTDI** · 29-01-2007,10:53 AM

Having trouble with one of our cars at the moment. Its a '99 Bora with the 110BHP Tdi engine.

The car runs fine, starting and cruising no problem but when the engine is under heavy loads, ie. accelerating to overtake or driving uphill the engine just loses power. Unable to maintain speed uphill and only just able to accelerate on the flat. It feels to me as if the turbo cuts out. The problem seems to occur at around the 3000rpm mark, the car accelerates quite well at that point with a real noticeable drop when this problem occurs. The strange thing is is that it does not always happen, seems to be more random, but only occuring under a heavy load. The other strange thing is that it clears itself by turning off the ignition and restarting the engine, which is not a pleasant experience on the motorway or a fast 'A' road.

I dont really know too much about the workings of turbo diesel units but I am first inclined to think its a problem with pressure in the turbo? perhaps a wastegate not opening?

Any techies out there have any clues?

Thanks in advance.

**BoraTDI** · 29-01-2007,03:33 PM

Anyone in Berks/Bucks with that VAG com thingy ?

**VW Techniker** · 29-01-2007,08:52 PM

Hi,

Sounds like yet another Mass Air Flow sensor fault.

**onzarob** · 29-01-2007,09:45 PM

If you have a laptop you can buy a cable for £39.00 and download the freeware version of VAG-COM. well worth it as you can read the codes and VW Dealer will charge you at least this to do it.

For cable look here http://www.gendan.co.uk/vag_diagnostics.php

For deatils on VAG-COM look here www.ross-tech.com

Rob

**BoraTDI** · 29-01-2007,09:53 PM

Thanks.

**Col** · 29-01-2007,11:00 PM

I'm in Maidenhead with VAGCOM and might be able to help.

The problem with MAF failures though is that they rarely produce any fault codes.

**BoraTDI** · 30-01-2007,12:32 AM

I suppose theres no way of testing the MAF then?

**BoraTDI** · 30-01-2007,12:34 AM

Forgot to add, that I was out and about this afternoon trying to reproduce the fault but could not trigger, high revs in all gears, accelerating uphill etc etc, nothing seemed to trigger it so it certainly is a random fault occasionally triggered in high revs or under load. From what I can remember the few times that it has happened have occured around the 3000rpm mark

**onzarob** · 30-01-2007,06:29 AM

when my MAF was gone it wouldn't rev over 3000, when i uppluged it it would rev over 3000 and was smoother. But still not full power. You can take reading from the MAF but you need vag-com and it still can be difficult. If it hasn't been chaged before it won't hurt and they do seem to have come down in price as they are well known for problems.

Rob