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Discussion Starter #1
Went to start my car one day a few weeks ago and it wouldn't start AAA towed it to VW and turns out the timing chain tensioner gave out and broke the chain and damaged the cylinder head. about 45K miles on the 2012, just got the estimate from dealer to fix everything they said with recent lawsuit coverage my max cost would be about $600 USD, they said this includes the new cylinder head as well as all new parts. The process for approval took about 3 weeks and repair will take another week, dealer was nice enough to give me a new top tier Atlas with on 10 miles on it as a loaner through the process at no change.
 

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I'm surprised it was as little as $600 but I guess you mean most is paid for and that's what they want you to pay, which isn't far off the cost of a full service? Timing chain and tensioner problems seem to affect V.W engines in other models, not just the EOS.

I hope they put back parts which work because some internet reports say they have tried more than one part modification to get this right?
 

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I'm surprised it was as little as $600 but I guess you mean most is paid for and that's what they want you to pay, which isn't far off the cost of a full service? Timing chain and tensioner problems seem to affect V.W engines in other models, not just the EOS.

I hope they put back parts which work because some internet reports say they have tried more than one part modification to get this right?
Yes, I was pleasantly surprised that my cost will be max $600, but I think they took into consideration that I have owned several VW in the past. Are you saying the cost to replace the tensioner would have only been $600, I think the overall cost for all the work they have to do would have been over 3K
 

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No, I would expect 3k+ for all that work plus parts. There are some here who complained that V.W would not do this mod. as a routine precaution. It sounds like they would rather wait for their engines to grenade before doing anything? IMHO if I was worried about impending timing chain doom on a highish mileage, I think I might have done the chain and tensioner myself to avoid the cylinder head failure. I think you were very lucky with the outcome.

The tensioner problem manifests itself at cold start after the engine has stood, the chain loses tension on the back slope because oil pressure has been lost. At first cranking before oil pressure comes up, the slack chain jumps a tooth or worse the engine misfires and jumps more teeth. Once the engine runs it is then doomed as pistons whack against the valves.

With my simple V.W cam belt system, the belt tensioner roller uses a big strong spring and a one way ratchet, just like self adjusting brakes. Any slack in the belt and the tensioner only moves a notch one way on the ratchet and never moves backwards.

The oil pressure type tensioner for chains is designed differently and I think their past problems arose when the ratchet or piston could move back to the very slack position? You wouldn't notice at first because oil pressure could eventually tension the chain, but cold cranking from zero oil pressure will find any design flaws with disastrous consequences. Why do they use this system for chains? Because in theory it reduces the size of the tensioner in the limited space under the timing cover. I'm glad my TDi has a quiet belt!
 
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