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Old 6th October 2019, 08:52   #21
SD1too
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Originally Posted by Rsnail View Post
I closely listened as far as I could reach with my ear towards the idler and the tensioner and the noise really doesn't seem to come from there.
Trying to judge the source of any mechanical noise using that method is unreliable. I offered you the benefit of my personal experience since my engine sounded a bit like yours (in the second recording) until I renewed the ancillary belt tensioner plus the timing belt pulleys. I also similarly diagnosed a friend's KV6 earlier this year. He was sceptical too until his garage confirmed it.
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Originally Posted by Yorkshire GOC View Post
Would also put your ear to the exhaust down pipe manifold gasket whilst you are at it.
Whilst I agree that nothing should be ruled out, I'd suggest a hand to feel exhaust gas pressure immediately after a cold start. However, I'm fairly confident that the 'check engine' light would illuminate under those circumstances and that hasn't been reported.

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Old 6th October 2019, 09:01   #22
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Originally Posted by T-Cut View Post
Already eliminated - see last line of Post 7.


tc
So it is, I missed that.

The reason I suggested it is that my V6 does the ticking thing every now & then, and when it does the noise from the valve becomes very loud indeed (using the stick in the ear trick).
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Old 6th October 2019, 09:58   #23
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Can I check the exhaust gas pressure with toaf or with torque app for example? And if yes, what values should it read?

Also, does the ancillary belt have it's own idler and tensioner? On dmgrs I only found the aux belt but neither a tensioner nor an idler for it I tend to think that the noise is coming from the rear belt, the one closest to the engine firewall since there's the place where the noise is coming from, and not from the aux belt area of the engine

EDIT: I succesfully pinpointed with a listening stick that the ticking is coming 100% from the rear belt, the one closest to the firewall (right under the right side of the inlet manifold when looking at the engine). Done a little research and found out that the assembly is made out of 2 pulleys that are timing the admission and exhaust camshafts, correct me if I'm wrong. If that is the case, which one of the pulleys would be more prone to premature breaking?

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Old 6th October 2019, 11:22   #24
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... does the ancillary belt have it's own idler and tensioner?
Yes.
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... the ticking is coming 100% from the rear belt, the one closest to the firewall (right under the right side of the inlet manifold when looking at the engine).
It's relatively easy to remove the belt covers and check the tension and condition of both rear belts.
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... the assembly is made out of 2 pulleys that are timing the admission and exhaust camshafts, correct me if I'm wrong.
You're correct. On each bank a rear belt drives the exhaust camshaft from the corresponding inlet camshaft.
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... which one of the pulleys would be more prone to premature breaking?
Neither. There is no tensioner either and my rear belts lasted 90,000 miles (and 20 years) easily.

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Old 6th October 2019, 12:09   #25
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@SD1too, Thank you lots and everybody for the help provided so far! In order for me to inspect the rear belt assembly near the firewall I can see that the battery carrier has to be removed and from there it's just about unscrewing the cover if I'm right. And if one of the pulleys has to be replaced, what would the procedure be? Do I have to somehow lock the cams or mark the position of the pulleys for when installing the new one?
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Old 6th October 2019, 15:38   #26
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In order for me to inspect the rear belt assembly near the firewall I can see that the battery carrier has to be removed and from there it's just about unscrewing the cover if I'm right.
For access and good visibility, you will probably have to remove the inlet manifold chamber as well. That's quite an involved job in itself.
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And if one of the pulleys has to be replaced, what would the procedure be? Do I have to somehow lock the cams or mark the position of the pulleys for when installing the new one?
You will be well advised to use the special service tools for belt replacement:
  • Flywheel/drive plate locking pin 18G1746A to keep the engine in the 'safe' position.
  • 12-175 to hold the rear pulleys stationary whilst you release the fixing bolts. The locking pin previously described is not a safe alternative.
  • 18G1747-1 to tension the assembly to enable it to be refitted. Alignment pins 18G 1747-5 are very useful too.
  • Use 18G 1747-4 (part of the front sprocket wheel locking tool on aftermarket kits) to reset the exhaust camshaft to its correct position (it will have moved when the belt was released) whilst refitting the assembly.

But my prediction is that you'll find nothing wrong with rear belt and certainly the sprocket wheels (unless incompetent work has been carried out in the past).

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Old 6th October 2019, 17:32   #27
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I removed the manifolds some months ago when I replaced the thermostat and besides time, that won't be any problem for me, but managed to get a good look at the sprockets only by removing the battery carrier and stripping the sprockets cover off, everything seems fine, belt is good with no cracks and the sprockets have no visible damage or wear, the only thing that got my eye is that both sprockets don't spin exactly around the center and they have about 1mm of excentrical movement, what would that mean and could it be that this is the reason for the ticking? Anyways, the ticking is coming 100% from there as it was way more hearable with the cover off...

Link for the video taken with the movement:

Video

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Old 6th October 2019, 17:57   #28
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... both sprockets don't spin exactly around the centre and they have about 1mm of eccentric movement, what would that mean ...
Possibly that they weren't refitted correctly when the belts were renewed? It's guesswork really Galambosi. Why not remove the LH bank rear belt cover as well, then you can compare the two.

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Old 6th October 2019, 18:33   #29
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You're right Simon, will do that tomorrow or when I get some more time on my hands and compare the two, I also wanted to check if one of the teeth on the sprockets is broken but obviously I can't turn them manually, although that would be really unlikely I guess

One more thing I noticed now on a cold start, which never happened before, is that the ticking appeared also each time when pressing the clutch pedal with the car staying still, and when letting go of the clutch pedal, it disappeared everytime. That's really confusing as the engine and the rear sprockets obviously are still spining regardless if the clutch is engaged or not

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Old 6th October 2019, 19:01   #30
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That's really confusing as the engine and the rear sprockets obviously are still spining regardless if the clutch is engaged or not
The difference is that when the clutch is engaged, a load is put on the engine.

I still can't rule out a tensioner or idler or worn ancillary belt causing the 'ticking'.

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