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Timing chain stretch on 1.4tsi engine at 55k miles

23K views 9 replies 4 participants last post by  voxmagna 
#1 ·
Just a heads up to those of you who may not know about this timing chain problem. I had an engine warning the other day which eventually resulted in a limp home mode (engine runs rich and rough). It was running so bad I went to my local garage and we came to the conclusion from the scanner codes (p000a etc) that it was a timing chain issue and as it was still running it was probably a stretched chain rather than the tensioner failed.
This engine had always been serviced annually by the dealership and the last service was only 2 months ago and was a major. I specifically asked them to check the timing chain and they said it was OK. (But how do they check it?)
Looking back now I have been noticing a slight chain rattle which would disappear when warm.
We contacted VW in hope they would do the replacement at cost but they refused as the car is 2010 engine 55k miles.
Anyway my local garage took on the job by drafting in a technician that had done one before. It involved fitting chain, gears, and tensioner kit from a reputable aftermarket supplier FAI.
It is not a cheap fix as it is about 7 hours work and includes flushing oil filter and lots of disassembling and gaskets water pump etc. And especially note that the preservation of multiple cam timing is tricky and requires a setting tool.
But Good News- Just got the car back and it is astonishing how quiet it is on startup. The lesson here is not to ignore that rattle. It could have been much worse if the chain let go!
BTW this is different fault from the tensioner failure which had a design fault where the ratchet spring clip breaks off. We did, of course, replace the tensioner with the new improved type so here’s hoping it will now last the life of the car as it was supposed to. But suffice to say timing chains about the size of a bicycle chain do wear out and are expensive to fix.
Still love my EOS but give my a toothed belt any day!
 
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#2 ·
Funny what you say because I was just finishing a long tedious job doing a cam belt, bearings, tensioner and water pump on a newer EA189 engine. I hadn't done it before on this engine. So much packed in I had to remove an engine mounting. :(My buddy saw what I was up to and said '....Glad I bought a car with a timing chain'. My answer was chains stretch and there's history of hydraulic chain tensioners failing to prime with oil and grenading engines. Et tu Brute! :) So we can't win either way. When they said they checked it, they probably just looked at the camshaft timing with diagnostics to check for timing variations, but eyes and ears are much more reliable than computers!
 
#3 ·
Yes agree we can’t win on this one - not specifically an Eos issue but difficult to ignore on our now aging but much loved convertibles.

PS
Just as a footnote that might help others worried about this issue. I have since found that there is an inspection port for the tensioner which, I am told, can be used to check for chain wear (with an endoscope?) and whether you still have the old faulty tensioner fitted. I understand the VW dealer does not remove this to inspect it unless you specifically ask.
more detail here http://forums.vwvortex.com/showthread.php?7245018-Chain-Tensioner-Inspection-how-to-help-needed
 
#4 ·
Thanks that's helpful info to others.

If I had your engine I would probably insist on an inspection at 45k and some confirmation from V.W that the tensioner mod. has or hasn't been done? If you grenade an older EOS engine it probably writes off the car and it's not worth taking a chance. You did the right thing. If the dealer tech. says 'These never wear or go wrong' - have it inspected anyway because it's you that takes the risk.
 
#5 ·
Just a heads up to those of you who may not know about this timing chain problem. I had an engine warning the other day which eventually resulted in a limp home mode (engine runs rich and rough). It was running so bad I went to my local garage and we came to the conclusion from the scanner codes (p000a etc) that it was a timing chain issue and as it was still running it was probably a stretched chain rather than the tensioner failed.
This engine had always been serviced annually by the dealership and the last service was only 2 months ago and was a major. I specifically asked them to check the timing chain and they said it was OK. (But how do they check it?)
Looking back now I have been noticing a slight chain rattle which would disappear when warm.
We contacted VW in hope they would do the replacement at cost but they refused as the car is 2010 engine 55k miles.
Anyway my local garage took on the job by drafting in a technician that had done one before. It involved fitting chain, gears, and tensioner kit from a reputable aftermarket supplier FAI.
It is not a cheap fix as it is about 7 hours work and includes flushing oil filter and lots of disassembling and gaskets water pump etc. And especially note that the preservation of multiple cam timing is tricky and requires a setting tool.
But Good News- Just got the car back and it is astonishing how quiet it is on startup. The lesson here is not to ignore that rattle. It could have been much worse if the chain let go!
BTW this is different fault from the tensioner failure which had a design fault where the ratchet spring clip breaks off. We did, of course, replace the tensioner with the new improved type so here’s hoping it will now last the life of the car as it was supposed to. But suffice to say timing chains about the size of a bicycle chain do wear out and are expensive to fix.
Still love my EOS but give my a toothed belt any day!
 
#6 ·
My engine light came on the other day , with start stop error coming up on dash cluster , after scanning it came back saying stretched timing chain ,
Just bought the car privately & was meaning to give it a oil service, but obviously left it too late , My recommendation would be for now on is oil service every 5000k , & your motor will love you for it ... Costly repair , but you learn the hard & expensive way unfortunately
 
#8 ·
Even though MY07 is diesel with a timing belt, I'm not doing high annual mileages and have gone away from V.W 'LongLife' synthetic oils and now use standard V.W spec. synthetic oils with oil changes every 5-6K. All modern engines with closed circuit breathing systems and their oils can retain a lot of carbon and gunk. Historically, those old hands who changed engine oils regularly always got the highest trouble free engine mileages and lowest engine wear. It was only the push from buyers complaining about service costs and downtime that forced the introduction of longer life oil products to reduced service intervals. I think any timing chain engine reaching 100k+ deserves a new chain and tensioner? Although I read V.W tensioners have been through different versions and second recalls, so I don't know if the problem is fixed completely? Belt engines like mine need parts replacement work at 45k and 60k. Later poly belt engines claim up to 80k before work, so I wouldn't complain about replacing a chain and tensioner at 100k.
 
#9 ·
Just a heads up to those of you who may not know about this timing chain problem. I had an engine warning the other day which eventually resulted in a limp home mode (engine runs rich and rough). It was running so bad I went to my local garage and we came to the conclusion from the scanner codes (p000a etc) that it was a timing chain issue and as it was still running it was probably a stretched chain rather than the tensioner failed.
This engine had always been serviced annually by the dealership and the last service was only 2 months ago and was a major. I specifically asked them to check the timing chain and they said it was OK. (But how do they check it?)
Looking back now I have been noticing a slight chain rattle which would disappear when warm.
We contacted VW in hope they would do the replacement at cost but they refused as the car is 2010 engine 55k miles.
Anyway my local garage took on the job by drafting in a technician that had done one before. It involved fitting chain, gears, and tensioner kit from a reputable aftermarket supplier FAI.
It is not a cheap fix as it is about 7 hours work and includes flushing oil filter and lots of disassembling and gaskets water pump etc. And especially note that the preservation of multiple cam timing is tricky and requires a setting tool.
But Good News- Just got the car back and it is astonishing how quiet it is on startup. The lesson here is not to ignore that rattle. It could have been much worse if the chain let go!
BTW this is different fault from the tensioner failure which had a design fault where the ratchet spring clip breaks off. We did, of course, replace the tensioner with the new improved type so here’s hoping it will now last the life of the car as it was supposed to. But suffice to say timing chains about the size of a bicycle chain do wear out and are expensive to fix.
Still love my EOS but give my a toothed belt any day!
Thanks for the heads-up. Can you please try to describe the sound made by the "slight chain rattle" as you described it, as well as where in the engine bay the noise was approximately located. I ask because sometimes on a cold start up (only cold) we hear a slight, light rumbling noise coming from the drivers side of the engine bay, close to the firewall. It always seems to stop after 15 seconds, and in fact upon our last 3-4 cold startups we didn't even have the noise. Trying
to get a handle on what may be the problem before handing the keys and my bank account info to the repair shop. Thx
 
#10 · (Edited)
IMHO timing chains should not be 'stretching' causing the primary fault. The weakest link in the timing chain is the tensioner of which there's plenty already written. Engine management monitoring timing can't tell the difference between a less likely chain stretch and a more likely tensioner problem which leaves the chain slack and causes the timing to oscillate. That's what the ECU is probably looking for to throw up the error code.

These timing chains like many others are designed with a hydraulic tensioner using oil pressure. When you start a cold engine, oil has to move from the sump to the camshaft and at the same time tension the chain. This puts the engine at most risk of timing chain jump (and errors) at first cold start. This cold starting risk is reduced by designing the oil filter with a backflow valve if it's a genuine V.W part and ensuring the timing chain hydraulic tensioner doesn't lose oil pressure or tension when the engine stops (hard to do relying on a small sloppy piston seal). The best and most reliable tensioners don't just rely on a small hydraulic piston holding tension on the chain but incorporate a one way ratchet device working in a similar way to some rear brake caliper auto adjusters. I've never seen the troublesome V.W tensioner so I can only suggest their design problem with relaxing tension is either in the piston, or ratchet if they use one. Another possibility is they use a small non-return valve in the oil supply pressure feed. The problem with those can be dirty oil stopping the poppet valve seating causing oil leak back? Keeping engine oil clean with more frequent oil changes should help. My timing belt uses a large strong coil spring and one way ratchet to hold tension on the belt - no hydraulic problems with those! There isn't much room inside timing covers and a hydraulic piston design is a lot smaller to fit in.

A workshop would usually replace a timing chain when replacing a tensioner, but IMHO it will be tensioner, worn guides and/or an aftermarket oil filter most likely causing short period oil starvation to the camshaft and chain on a cold start, because oil has drained down (e.g overnight). If you only get the rattle on first cold start of the day but not when restarting after a much shorter time, the tensioner design is most likely the problem. I think the reason V.W don't seem to have been so aggressive at recalling is the risk is mainly present during first cold starting. Using thicker engine oil in cold climes doesn't help either.

If you research you will find that V.W timing chain tensioners have been through more than one iterative change and unless previous work has been done at a dealer you won't know which version is fitted. On an engine that's done less than 80k I would go for the tensioner and guides before the chain. Talk to your workshop about V.W timing chain tensioners and their series of modifications. I don't know if the latest version fixes all the problems for 100k miles+ or not because it takes some miles to find out.
 
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