TB Tensioner Broke, but looks like I am ok

Hi,

My 2002 TDI started sounding like a large truck on the freeway. I immediately started coasting and got off the freeway at the next exit (about 5 minutes with minimal load on the engine) before I could turn it off. Had it towed to the place where I purchased it and they diagnosed a bad tensioner part (they had just done the 80K replacement of TB, Tensioner, and water pump). They replaced the part and it runs fine now. Question for the group is can something like this cause a long term problem or if the engine runs now am I ok.

Thanks,

ski

You're screwed. Sounds like that mean the valves were contacting the pistons. The tensioner COULD have failed but it's unlikely unless they cammed it around from the bottom or didn't get it locked in the hole.

I HIGHLY doubt they have a vagcom and lock down tools so the job at best is marginal.

DEMAND they cover any valve train related failure for the next 10K miles. By then something will break if it's going to. I'd go elsewhere and have the cam pulled and look for lifter damage too. VERY PROBABLE.

Kudos on your quick response. You may have saved yourself a big bill.

Does the car run as it did before?
It may appear to be OK, but if the valves made contact with the pistons at all, they could be weakened and may fail prematurely.

I would ask the place that did the TB work to extend the warranty in case this failure does happen in the future.

Do you know if they replaced the engine mount bolts when they did the TB job? Is this a VW dealership or an independant shop?

I'd go elsewhere and have the cam pulled and look for lifter damage too.

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What he said.

I have seen one time where nothing made contact. But what I would do is have a compression test done. That will let you know if you have any bent valve. I have seen a couple of times that the valves looked OK but when you took them out and did a run out with a dial indicator they were bent.

Greg

Compression test, pull valve cover and check for deformation of the lifter/cam contact surface.

As JasonTDI said, there is no reason for the tensioner to fail if the just did the job properly. If they didn't do it right the first time, it seems unlikely they will get it right the 2nd.

Do a compression test when cold, then when hot.
You can get a compression tester for diesels at harbor freight for like $30.

Good luck... I helped replace an engine that had a failed tensioner. the engine never ran right when cold. even with a head job

Thanks for the comments. The car runs just like before with possibly one exception (not sure if I am being overly sensitive or not). The exception is I smell diesel for just an instance when I get out after a turning off the engine and I do not remember smelling the diesel before.

I already have a 5.5 month warrantee left on the car. I bought it from an independent dealer who specializes in diesels (mostly VW TDI's) so I am pretty sure they have the tools. They also have a good repuatation in the community. I am the second owner and they had all the paperwork from the first owner for all the maintenance. I will check and see if they did a compression test, visual inspection, see about extending the warrantee.

chromeBuddha said:

Compression test, pull valve cover and check for deformation of the lifter/cam contact surface.

As JasonTDI said, there is no reason for the tensioner to fail if the just did the job properly. If they didn't do it right the first time, it seems unlikely they will get it right the 2nd.

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Yes you can check them but it will not tell you if the valve is bent, only that the valve was hit.

Greg

you can take off the valve cover, and you should be able to see a dent in the lifter, if it's a hard hit it will have spiderweb cracks on the chrome surface. if either one of these is there, then you have a valve that is a ticking timebomb.

Having heard the horror stories of the valve heads later detaching due to unseen internal damage, I would replace any valve that had piston contact, even if it measured 100%. $12-20 x 4 sounds a lot better than the potential of replacing lower end components of the valve head jams between the piston and the head at speed...and redoing all the head work...

LanduytG said:

Yes you can check them but it will not tell you if the valve is bent, only that the valve was hit.

Greg

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