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!!Timing Chain Tensioner!!

Posted: Wed Aug 03, 2016 10:35 pm
by Psycho Kirky
Hi all, recently ive had the unfortunate displeasure of the timing chain tensioner failing in my 2.0 tsi. This was confirmed once the tensioner was removed and inspected.

Pictures to follow.....

If this happens to you and you want to do it yourself or help someone do it then you will need special tools just to access the tensioner. These cost me just over £100 from VW.

I also bought the necessary new parts and others such as the serpentine belt and belt tensioner and balance chain, seeing as the engine is apart its the best time to do all these.
That was another £500. Not happy but taking advantage of the engine situation.

Finances are dwindling a bit now :(

After getting the new tensioner in earlier today, we timed the engine and after the minimum 2 crankshaft revolutions rotated by hand obviously, we did a compression test.

We did one the other day and cylinder 4 read 0 bar of compression.
The same happened once timed.
This indicates the probability of a bent valve(s).

ABSOLUTELY FUMING!!! :O

So now we have removed the inlet manifold amongst everything else in the way of the head.
Aaaaaand the head will be removed tomorrow (probably) this is taking the piss all because of a tiny bit of metal failing in the tensioner. Thanks VW.

Anyway it is going to end up costing me even more money now and I am possibly going to have to buy another car because i am eventually going to have to go back to work lol.

Please for the Love of the non existant God, get your tensioners updated to the latest version atleast for peace of mind.





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Re: !!Timing Chain Tensioner!!

Posted: Wed Aug 03, 2016 10:38 pm
by Psycho Kirky
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Re: !!Timing Chain Tensioner!!

Posted: Wed Aug 03, 2016 10:39 pm
by Psycho Kirky
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Re: !!Timing Chain Tensioner!!

Posted: Wed Aug 03, 2016 11:34 pm
by blower
Damn! sorry to hear that's happened......not that i want to add to your pain, and you may get lucky but be prepared for piston and/or cylinder head damage, have seen that all too often on chain failure with TSI engines :(

Re: !!Timing Chain Tensioner!!

Posted: Thu Aug 04, 2016 9:03 am
by Jammy
Out of curiousity what age and how many miles had yours covered before it happened?

Re: !!Timing Chain Tensioner!!

Posted: Thu Aug 04, 2016 9:15 am
by tommy
Jammy wrote:Out of curiousity what age and how many miles had yours covered before it happened?
Psycho Kirky wrote: Its a 2011 so im guessing its original, not revised.
My mileage is about 79k, i didnt hear or notice any noises or rattling or performance issues prior.
So it must have been weakened and finally gave up fairly quickly.

Luckily i am getting it recovered home by the AA and fixed nearby i hope.

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That's really rubbish Kirky sorry to hear that mate :grumpy: I think I should probably go to VW and get a quote for getting mine done then before this happens... :shrug:

Re: !!Timing Chain Tensioner!!

Posted: Thu Aug 04, 2016 9:18 am
by Psycho Kirky
tommy wrote:
Jammy wrote:Out of curiousity what age and how many miles had yours covered before it happened?
Psycho Kirky wrote: Its a 2011 so im guessing its original, not revised.
My mileage is about 79k, i didnt hear or notice any noises or rattling or performance issues prior.
So it must have been weakened and finally gave up fairly quickly.

Luckily i am getting it recovered home by the AA and fixed nearby i hope.

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That's really rubbish Kirky sorry to hear that mate :grumpy: I think I should probably go to VW and get a quote for getting mine done then before this happens... :shrug:
Sad times indeed :( These tensioners need replacing but it is a costly job, it takes a fair few hours too, its the labour charges that will bite you! Luckily my mate wont charge me anywhere near a garages prices :D

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Re: !!Timing Chain Tensioner!!

Posted: Thu Aug 04, 2016 9:44 am
by tommy
Psycho Kirky wrote: Luckily my mate wont charge me anywhere near a garages prices :D

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Where is you/your mate based? :D Fancy doing my after? :lol:

Re: !!Timing Chain Tensioner!!

Posted: Thu Aug 04, 2016 10:01 am
by Psycho Kirky
Midlands, but no chance mate lol, I hope to never have to do this again haha!

We are both sick of it lol [emoji14]

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Re: !!Timing Chain Tensioner!!

Posted: Thu Aug 04, 2016 10:16 am
by tommy
:cry: sad times but fair enough... ;) VW here I come :cry: :cry:

Re: !!Timing Chain Tensioner!!

Posted: Thu Aug 04, 2016 11:14 am
by Roy_01
Stupid that this timing chain tensioner still isn't recalled by VW.
I had the same in juli with a rental car luckily.

Re: !!Timing Chain Tensioner!!

Posted: Thu Aug 04, 2016 11:44 am
by blower
Some background information on these tensioners and why they fail.....

The tensioners in 1.2 TSI, 1.4 TSI and early 2.0 TSI/FSI engines have an issue with potential chain slip due to the tensioner having no oil hydraulic pressure when the engine is shut off. The tensioners contain a spring which pushes the plunger onto the guide rail and add some preload when the engine is shut off. Over time this spring can weaken and there is a potential for the chain to slip on startup. This problem is hugely exacerbated if the car is left in gear and it rolls backwards - the reverse turning of the crankshaft will result in the chain coming loose from the crankshaft chain sprocket such that when you start the engine it will slip a tooth or 2.

Now all chain driven 1.2 and 1.4 TSI engines still have this issue - no changes have been made to the tensioner design to alleviate this problem. Which is why on these engines you should never ever leave the car in gear when parked - if it rolls backwards there is a good chance the chain will slip. Nearly all tensioner failures on these engines have resulted from the car being left in gear on a sloped driveway or hill. Unsurprisingly all the failures I have seen on these engines have been manual gearboxes - dsg versions cannot be left in gear when parked.

VW in all their wisdom decided to experiment with the 2.0 TSI engines and introduce a ratchet mechanism into the tensioners - which allows the plunger to extend outwards overtime to compensate for chain stretch, but not retract....which means it always retains a certain level of pressure on the guide rail, regardless of hydraulic oil pressure. This resolves the above problem.

However, this ratchet mechanism is prone to completely failing with the outer clip breaking off and the whole tensioner falling to bits. Ironically a change in design to fix the potential issue of chain slip at startup, resulted in a significant drop in general tensioner reliability and increased the likelihood of catastrophic failure.

VW have revised this design over the years, and there have been a few revisions of this ratchet version of the tensioner - however I don't think even the latest version is entirely reliable.

Re: !!Timing Chain Tensioner!!

Posted: Thu Aug 04, 2016 11:52 am
by Psycho Kirky
blower wrote:Some background information on these tensioners and why they fail.....

The tensioners in 1.2 TSI, 1.4 TSI and early 2.0 TSI/FSI engines have an issue with potential chain slip due to the tensioner having no oil hydraulic pressure when the engine is shut off. The tensioners contain a spring which pushes the plunger onto the guide rail and add some preload when the engine is shut off. Over time this spring can weaken and there is a potential for the chain to slip on startup. This problem is hugely exacerbated if the car is left in gear and it rolls backwards - the reverse turning of the crankshaft will result in the chain coming loose from the crankshaft chain sprocket such that when you start the engine it will slip a tooth or 2.

Now all chain driven 1.2 and 1.4 TSI engines still have this issue - no changes have been made to the tensioner design to alleviate this problem. Which is why on these engines you should never ever leave the car in gear when parked - if it rolls backwards there is a good chance the chain will slip. Nearly all tensioner failures on these engines have resulted from the car being left in gear on a sloped driveway or hill.

VW in all their wisdom decided to experiment with the 2.0 TSI engines and introduce a ratchet mechanism into the tensioners - which allows the plunger to extend outwards overtime to compensate for chain stretch, but not retract....which means it always retains a certain level of pressure on the guide rail, regardless of hydraulic oil pressure. This resolves the above problem.

However, this ratchet mechanism is prone to completely failing with the outer clip breaking off and the whole tensioner falling to bits. Ironically a change in design to fix the potential issue of chain slip at startup, resulted in a significant drop in general tensioner reliability and increased the likelihood of catastrophic failure.

VW have revised this design over the years, and there have been a few revisions of this ratchet version of the tensioner - however I don't think even the latest version is entirely reliable.
I am convinced that any of their tensioners will be flawed in some way but hopefully it will last alot longer than the original! Good info though!

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Re: !!Timing Chain Tensioner!!

Posted: Thu Aug 04, 2016 12:42 pm
by Harry_VW
anyone know if i can get VW to change my tensioner under used car warranty as a preventive measure?

Re: !!Timing Chain Tensioner!!

Posted: Thu Aug 04, 2016 12:51 pm
by blower
Harry_VW wrote:anyone know if i can get VW to change my tensioner under used car warranty as a preventive measure?
No chance....VW won't do anything under preventative maintenance, unless you pay for it of course.

If there is an official nationwide recall they will do it, but without a recall they won't do a single thing unless its already failing or failed.
It's hard enough to get them to fix things when there is a fault! - as unless it's blatantly obvious they usually come back with either 'nothing wrong and we couldn't find a fault' , or 'that's normal operation they all do that'

Re: !!Timing Chain Tensioner!!

Posted: Thu Aug 04, 2016 12:57 pm
by Harry_VW
blower wrote:
Harry_VW wrote:anyone know if i can get VW to change my tensioner under used car warranty as a preventive measure?
No chance....VW won't do anything under preventative maintenance, unless you pay for it of course.

If there is an official nationwide recall they will do it, but without a recall they won't do a single thing unless its already failing or failed.
It's hard enough to get them to fix things when there is a fault! - as unless it's blatantly obvious they usually come back with either 'nothing wrong and we couldn't find a fault' , or 'that's normal operation they all do that'
Yh I'm having that problem at the moment. http://www.sciroccocentral.co.uk/forum/ ... =2&t=22763" onclick="window.open(this.href);return false;

I've taken it in twice now and they say they cant hear anything. :grumpy:

Re: !!Timing Chain Tensioner!!

Posted: Thu Aug 04, 2016 2:04 pm
by dimexi
quick question for blower:

You say about leaving a car in gear and it rolling back possibly exacerbating the situation... How about if you just roll the car back when it's not in gear (just by releasing the handbrake on a hill), will this make the chain slip?! I assume not as the flywheel wont be connected..

Also, I thought a car in gear on a hill couldnt move, except you push it

Re: !!Timing Chain Tensioner!!

Posted: Thu Aug 04, 2016 3:34 pm
by Roy_01
Yes car will still move slightly forward or backward and is being held because it will not turn the engine through its compression.

Re: !!Timing Chain Tensioner!!

Posted: Thu Aug 04, 2016 4:16 pm
by blower
dimexi wrote:quick question for blower:

You say about leaving a car in gear and it rolling back possibly exacerbating the situation... How about if you just roll the car back when it's not in gear (just by releasing the handbrake on a hill), will this make the chain slip?! I assume not as the flywheel wont be connected..

Also, I thought a car in gear on a hill couldnt move, except you push it
It's fine to let it roll when not in gear - no gear engaged means it won't turn the crankshaft and hence it wont turn the chain.

A car can move in gear - just takes more effort, people tend to leave it in gear to make it harder for the car to run away if the handbrake fails. Problem is it doesn't have to move much for it to make the chain slip....if you actually left it in reverse gear and it was parked up hill then that would be fine as the crankshaft would be turning clockwise as the car rolls back.

Basically the crankshaft should never be turned in reverse (counter clockwise) when the engine is off, leaving it in any forward gear whilst parked uphill or on a driveway with an upward incline will do this if it slips back slightly.

Re: !!Timing Chain Tensioner!!

Posted: Thu Aug 04, 2016 9:36 pm
by aaimson
Did your tensioner fully fail, or was it just in the process of going? Mine is currently going (can hear the chain a little loose on start up) but I'm doing minimal driving, it's going into the garage this weekend so hoping its just new chain and tensioner!