Replace Timing Chain Tensioner

[loroco]

I have the engine chatter when the engine starts up and disappears after the oil pressure is up. I've read through the threads on timing chain replacement but am looking at replacing only the tensioner.

If I don't replace does it get worse?

How difficult is it to replace the tensioner only, is it a weekend job and any special tools required? Any info you can share will help me decide whether to tackle this job.

[mike65]

The chain tensioner is easy (I did mine yesterday)
but you need 2 items you may not have - a) 32mm socket
with short extension. b) a 17mm hex bit.

Otherwise its straightforward. Loosen polybelt remove top bolt on alternator, loosen bottom bolt (from behind) drop the alternator away from engine and you'll see the tentioner body "head" which is what you need the 32mm socket for. Remove that (prepare for it to spring out!) recover the washer.

Then using the 17mm hex bit on a socket wrench
loosen and remove tensioner body.

Fit new tensioner body, tighten up.

Clean up the 32mm socket (it'll get covered in oil from the tensioner) place new washer on tensioner body, place new spring on the locating pin inside the 32mm head drop head inside the 32mm socket (you'll need to have clean dry hands for this bit) and then locate the spring end inside the tensioner body and push in against the spring (its pretty hard!) and then turn the head until it locates on the tensioner body thread. Tighten good and proper (or it'll leak oil).

Then refit alernator and polybelt.

This is the short desciption naturally! You'll also need to remove radiator fan and shroud for decent access.

Mike.

[falconjoe]

Also remember to put the proper torque on the bolts, otherwise you may make the tension on the timing chain too tight.

[theairboy]

hello loroco

a few things to keep in mind.

all chain tentioners new or old are only capable of extending out so far, and after setting for some time the oil presure has deminished from the tentioner so the only thing holding the tentioner out at start up is the spring. becouse of the incresed lenth of the chain with age and the decresed thickness of the guides the chain tentioner is eventualy expanded close to its limits and the farther it extends the more the spring is uncoiled giving you less spring tention. so even if the noise decreases a little after you change the tentioner you are only proloning the enevitable.

so if you think about how expensive a head rebiuld with new valves (and chain assembly) is there is only one thing to do. do the correct repair now while its possible.

this post was in no way ment to be condisending i just hate to see a fellow benz owner weeping over a preventable disaster[V]

[theairboy]

oops i almost forgot.

if your a used car salesman. disregard my previous post and stick a shim between the tentioner pin and the guide rail[:D]