LightDragon

what 3 ? arent they the 32 and 26 ?

LightDragon

and by the way what might be the cause of the tensioner failure ? the accident ? how did it affect it ? isnt it a little strange ?

Glyn M Ruck

17,14 & 26 & their sub assemblies all guide & tension the chain. The chain is tensioned both mechanically & hydraulically.

I doubt that the accident had anything to do with it unless the impact dislodged something that was loose already. They just sometimes fail. Sh-t happens.

I had a new W202 in 1998 with the pre Kompressor version of the M111 engine. The chain tensioners & the camshaft adjuster failed in the first 2000Km's of that cars life & became noisy. They replaced the chain & tensioners & did the Benz deburring exercise on the adjuster. All was quiet for 2 weeks & the cam adjuster started making a noise again so they replaced that too. That was the end of the problem & it never recurred.

On high mileage engines that have not been adequately maintained with proper oil change interval & correct approved oil the chain sprockets on the cams & crankshaft can become worn. Then even if you fit a new chain the sprockets wear the new chain until it starts slapping around & giving the tensioners a hard time. If that is the case then you need to replace the sprockets & the chain & tensioners.

You need to open up the cambox & chaincase & inspect everything properly after using an engine stethescope to ensure that that is where the noise is coming from.
Good luck!

LightDragon

thanks man I really appreciate your concern. The fact is that when i disconnect the belt from the s/c the noise goes off by 80%. if it was the tensioner would this happen ?

LightDragon

The noise is coming from the red-circled area. something which is under there is causing it

LightDragon

the headers are exactly under this area, could it possible be them causing the noise ?

Glyn M Ruck

The noise you have recorded is not typical of a leaking header flange.

LightDragon

maybe it aint the flange but the tubes that are leaking. it aint either a timing chain noise cause i opened the oil cap and it wasnt louder

LightDragon

if it was the timing chain why wasnt the sound louder when I opened the oil cap ?
also there is no logical explanation for the issue to be the timing chain mechanism because when i disconnect the s/c the sound goes off by 80% which wouldnt make any sense

Carsy

Have you borrowed or bought a stethescope yet?.

This site has many knowledgable participants but few have ESP (Extrasensory perception).

LightDragon

tried with the "stethoscope" as well. i dont hear anything strange over the chain-case or valve cover

Glyn M Ruck

Please try removing one spark plug coil at a time so that the engine does not fire on that cylinder & see of the noise reduces.

LightDragon

tomorrow I will try the following:
1. Check the Headers for leaks
2. Remove the sparks one by one
3. Replace the timing chain tensioner

If I try all of the above and the noise still goes one, Im selling the car

Glyn M Ruck

Please replace the timing chain at the same time. Never fit a new tensioner to an old chain.

I have listened to you clip many times & it sounds mechanical & typical timing chain box noise.

However - in the area you think the noise is coming from the only thing I can think of is a piece of Cat honeycomb that has broken of & is rattling in the exhaust. It simply does not sound like headers.

Are you absolutely sure that the car is not storing any codes?

EDIT - & don't remove the spark plugs, just cut power to them one by one & listen to the noise change. We need full compression on all cylinders.

Carsy

Thinking out of the square about your red circled location , I had a piston skirt part from the rest of the piston once in a 4.4 L Rover/Buick engine. The broken piece did not part from the piston as it was held by the jigsaw effect. The knocking noise became more pronounced as the wear increased.

Just a thought...a piston.

Glyn M Ruck

Yes JC - Thats why I want him to unload cylinder by cylinder. It would show up small end bearing, piston etc. failure.

LightDragon

well, i checked the the headers and they are alright... all i can think of at the moment is a bad alternator as i removed the right belt today again and it was pretty much silent...

Carsy

Voi·là

LightDragon

trying to locate an alternator to switch it with mine and see if the problem disappears, they are pretty rare!

Carsy

What does the alternator sound like under the stethescope ?

LightDragon

stethoscope sucks, wasnt able to locate nothing with it. I dont recognize the noise when using it. I bet its a bad alternator as the noise goes away after removing the right serpentine belt - as in different case( if it was coming from inside the chaincase ) it wouldnt go away.

Glyn M Ruck

Carsy recommended removal of the Poly V belts in post number 10 & we are now at post 71.

LightDragon

I know Glyn but that stupid mechanic of mine told me he stills hears the noise after removal of the belts. when i told him to do it again he sais " oh i dont seem to hear it now" arrgghhh

Glyn M Ruck

Kick his butt - I'll bet he was too lazy to take the belts off!
Good luck!

LightDragon

thanks man. Monday its the BIG DAY! After replacing the alternator and put the car back together Ill stand by the ignition key... hold it in my hand, say my prayer and turn it slowly while my agony and tension hit red! The greatest moment.. a moment of silence as after starting the car Ill be either too happy or too sad...