C180 Timing Chain Tensioner

[pugspares]

Just replaced the timing chain tensioner to cure a rattle ('94 C180 Auto). Now the chain seems very tight and there is a loud whining noise when you start the engine.

Replaced tensioner at 20 BTDC, but last few turns inserting outer were quite tight.

Anyone got any ideas? Is there more than one tensioner for this engine - maybe I have the wrong one?

Iain

ps. rattle is still there so maybe it is a lifter after all!! I binned the old tensioner or else I'd put that back in!!

 

[Koolvin]

the rattling could be a waterpump!!!

comon fault.

 

[Andy]

Hi

Can't think if the tensioner is manually hydraulic or is fully hydraulic. But it sounds to me that the chain is too tight.

Recheck the fitment. ASAP. Otherwise the chain may snap.


Regards

Andy @ www.mercedesservicing.com

 

[pugspares]

Thanks Andy - chain clearly too tight when I fired it up, so haven't driven it pending fix!

Local dealer advises only one type of tensioner fitted, so I guess it must be the right one. It is strange that it over-tensions the chain even before inserting the spring and centre damper.

Very bemusing, I'll have to take the chain covers off and see what is going on. I'm not familiar with this engine, but I wonder if it's possible the tensioner plate has become dislodged or the tensioner is not properly located into the back of it. Anyway, I guess I have to replace the chain as well now, since it will have been over-tensioned.

Iain

 

[piestore]

chain tension

Hi
The order that the chain tensioner is assembled is very important as it has a locking system to stop it retracting, from your symptoms you probably assembled it as a complete unit and then screwed it into the cover this will over tension the chain. Remove the tensioner and strip (not you, the tensioner) fit the outer housing and alloy sealing washer back into the front cover, insert the plunger then the spring and rubber buffer finally ( after eating 3 wheatabix) get the allen key with the tensioner cap on and push into place while turning this may take two or three (hundred) attempts, once the thread has started wind up till tight. Once the engine has started check for oil leaks as the tensioner has full oil pressure and can leak a lot. All this assumes you have a 111 engine.
good luck

 

[pugspares]

no, tensioner assembled and fitted correctly (by the way, no problem with spring insert, as used to working on French cars, the Merc is a piece of pud!).

I have come to the conclusion there is another prob somewhere, because the chain is overtensioned after just inserting the outer - will have to remove the chain covers and investigate. But any ideas greatly appreciated.

Iain

 

[Koolvin]

2nd reply down, failing that get a stick and put it around bits of the engine and the other end of the stick to your ear, or use a stehoscope (SP)

 

[pugspares]

the rattling, yes good idea. 1st I have to sort the timing chain tension problem!

Iain