Sorry to repeat an old topic but I could do with some help.
I've owned my July 2002 Passat TDI Sport from new. It's done 42,000 miles and ran perfectly until a recent service, i.e. it pulled strongly up to 2,000 revs, then a fantastic surge of power and torque kicked in giving excellent performance, even in high gears, when it still pulled like a steam train from low revs.
It was a standard service except for the replacement of brake pads. On collecting the car it was immediately apparent there was no surge of power at 2,000 revs and it drove like an old donkey. There now seems to be a kick in and a significant increase of power from 3,100+ revs onwards, though I'm not sure if this is due to the turbo or just the increase in revs. Only by revving the car hard and excessive use of the gearbox to keep it above 3,500 revs can I get the sort of performance I experienced before. It is particularly reluctant to pull a high gear in low revs and needs to be above 3,500 revs to get any decent movement in a high gear.
I?ve now been back to garage twice and had 2 different mechanics look at it. The first one checked the MAF sensor and insisted it was correctly fitted and suggested there was nothing wrong with the car and I should just thrash it a bit more! The second one was more professional, he checked the MAF sensor and ran all the Bosch computer analysis and could not find anything wrong. However he agreed with me that it was way down on power, especially at low revs and couldn?t hear the turbo whining at around 3,000 revs as he would expect. The garage are now at a loss to offer an explanation. I have been invited to bring the car back a 3rd time to have the oil and oil filter that was fitted during the service changed. They claim to be VW specialist and insist they only ever fit the correct PD oil recommended by VW, but wanted to eliminate the possibility of being delivered oil with the wrong viscosity, which apparently might affect the running of the turbo???
Two final thoughts ? when the first mechanic [who also did the original service] checked the MAF sensor I noticed one of the cables had a small part of the outer cover stripped, I think possibly exposing a small part of the inner cable about 2cm long. When he realised I had seen this he told me it was where the cable had been rubbing and was there before. Could this affect the performance of the sensors/electronics??? Finally are any of the turbo lines near the air filter as this is changed during the service and could one have been damaged in the process???
A local VW main dealer has offered to conduct an investigation ? at £110 an hour + VAT! All I want is my car running as it was before. Any ideas would be gratefully received as the garage have run out of ideas and I see me either having to put up or pay VW big money with no guarantee of success ? or a refund from the servicing garage.
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This can be a hard one, and may require a full investigation. However, my experience has shown that when this sort of thing arises straight after a service, there is usually a reason - often a very simple reason and a thorough visual inspection will often reveal the cause.
Your vehicle is now about 5 years old. German rubber is poor quality.
The rubber vacuum hose covered with black cotton "fuzzy braid" so beloved by German manufacturers sinse the days of the air cooled beetle is terrible stuff. It looks OK on the outside but the essential rubber inner goes hard and cracks. There is then a leak to atmosphere through the cotton, which you can't see.
It will work in the hard, perished state until it's disturbed (read "having your vehicle serviced, perhaps not very carefully"). After this treatment, leaks often occur. I would do a very thorough inspection of the hose serving the VNT turbocharger actuator and also the EGR valve - although on some engines, better quality hose is used for this. Don't fall for the "you need a new turbocharger" story - they don't often fail, although the VNT actuation system sometimes sticks - which can be freed.
Best of luck.
659.
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Re the actuator 659 mentioned: here is a link with pictures and a method of freeing off, IF this is the problem. www.technologie-entwicklung.de/Gasturbines/VNT15-T...l
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