another timing chain question m119 - PeachParts Mercedes-Benz Forum

Victor300E · #1 12-27-2005, 01:28 AM

Hello. Sorry to bother with chain question again. But is it possible for timing chain to stretch to a point that it will make noise itself with engine running? Is there a way that chain tensioner to max out due to streched chain thus not tensioning chain fully? I do not have tool to check chain stretch.
My car is 92 500sel. 150k ml. Replaced: upper guides, inner guides,(did not change lower guide and tensioner guide but looked with flashlight and they seemed OK), chain tensioner,0w40 mobil 1 syntetic oil.
Problem: sounds like chain makes noise on cold moning start up, oil pressure comes up and I can hear how tensioner tenses chain, oil pressure drops for half a second then goes back up to 3 and then noise is gone

Does it sound like the chain is overstreched? PO drove car with broken guides and seemed like he did not change oil right(oil filter was deformed and cloged). Also when I was changing guides timing marks on camshafts were off by like 1/4 inch on passenger side cylinder bank while chain is tensed(turned engine with starter but didnt start it)
Sounds like I need new timing chain, right?
I am sorry for long post. It just drives me nuts. I work on car myself and learning new things about it everyday. And mechanic says chains last for 300k ml!
Very confused. Please help.
Thank you

duxthe1 · #2 12-27-2005, 08:17 PM

If you're experiencing a rattle on most cold startups then it is very likely that the oil pressure check valve is sticking open allowing the oil in the filter housing to drain back into the pan. On startup the engine has to "prime" itself and for the few seconds before before there is pressure the chain isn't held tight by the tensioner and it rattles. There is actually an updated part for the repair. It has a longer body to prevent it from cocking sideways and sticking open (which is how they fail).

I don't think the chain itself would cause the problem with the stretch you describe. I had one once where the pass. side ex. cam was 27 degrees late, without noise. Well other than it rubbing the valve cover.

Victor300E · #3 12-28-2005, 03:52 PM

Really. Oil releif valve inside oil filter housing was replaced. New tensioner. Guides are OK. Cheked them yesterday. I ordered new chain. How do I put master link on it and what do I use to connect new chain to old? Same master link?
Thank you

duxthe1 · #4 12-28-2005, 10:38 PM

Man, sounds like you've got a tough one. I'd have to hear the noise before I could offer any more advice.
I think the master links that are braded together are the best. There are links available that are assembled with c-clips. They are tiny and easy to drop so do yourself a favor and stuff several rags rag under it when both doing and undoing either type of master link.
I wouldn't use the new link to wind it in. You only want to stretch the new circlip once to put it on. I usually use the link I cut out to break the chain. One thing to note is that the endplates on the chain are press fit, not slip fit so you'd better have at least one if not two good pair of channel lock pliers handy to press it on.

Victor300E · #5 12-29-2005, 05:37 PM

I hope new chain will do it. I'll keep you posted.

Victor300E · #6 03-02-2006, 12:26 AM

Well, I went to mechanic to clean oil sump screen since timing guides broke. Boy what a mess

WHole screen was fully cloged. I have no idea how oil could even get through but I did after a little time after start up. Now oil pressure goes up right away and there is no rattle at start up. But now timing chain makes noise. Sounds like inner guides broke. Sounds like chain is grinding agains somethind or intermediate gear bearing is shot. Can it be possible for intermediate gear bearing to give up due to low oil pressure? It started making noise after ling trip on freeway. Most likely I will be opening timing chain cover to see whats inside. Any advice on timing chain cover removal?
Thank you
Victor

Ralph69220d · #7 03-02-2006, 09:36 AM

In the past I've used a piece of heater hose as a stethoscope to locate just where a noise is coming from. Just have to be careful if working around the fan or any drive belts.

Victor300E · #8 04-01-2006, 07:54 PM

Very soon will be changing chain and guides again. At least inspecting them. Noise is coming from driver's side top, more toward the middle of the engine. It sounds like something is grinding against something.

My thought is that one of the guides broke due to low oil pressure. I did not change driver's side lower guide. Now I will. Not the one in crank case. Too much work. And driver side and passenger side camshafts do not align by like 1/8 of an inch. So I think chain is too stretched. Now I'm looking for chain crimper.
I read somewhere that guide in crankcase never fails due to it's size and it's always in oil. What do you guys think?