OM617 timing chain stretch results. - Page 2 - PeachParts Mercedes-Benz Forum

Stevo · #16 10-13-2007, 01:09 PM

Quote:

Originally Posted by KAdams4458

It was actually your post that came up on a search that made me say, "Hey, why don't I look for a used cam?" Prior to that I was really only considering a new cam. The cost was giving me fits, though.

So, it ran much better with a good used cam, didn't it? How big of a difference would you say that you noticed?

I really cant say it made any difference. I was pretty new to MBs then, maybe I just didn't notice.

That 78 240D had more spunk than most 240s before and after the cam swap. I didn't see the badly grooved cam lob until I went in too adjust the valves.

pawoSD · #17 10-13-2007, 01:55 PM

Quote:

Originally Posted by ForcedInduction

There is no specification or interval for the chain to be replaced.

Hmm....ok then. I am an over-maintainer though....my car's chain had 7 degrees when I got it, so I had it replaced. Ran way better after that. Plus I can know that I have a new chain in there.

#18 10-13-2007, 02:00 PM

Quote:

Originally Posted by pawoSD

Hmm....ok then. I am an over-maintainer though....my car's chain had 7 degrees when I got it, so I had it replaced. Ran way better after that. Plus I can know that I have a new chain in there.

IMHO, it's less hassle to just replace it every 200K miles or so, instead of messing around with offset keys.

tangofox007 · #19 10-13-2007, 11:39 PM

Quote:

Originally Posted by KAdams4458

Testing with the gauge, I could watch the reading wonder significantly...

Never trust a gauge that wonders!!!

KAdams4458 · #20 10-14-2007, 02:38 AM

Quote:

Originally Posted by tangofox007

Never trust a gauge that wonders!!!

My apologies. I meant wander, of course. Sometimes my fingers type without listening to my brain.

On the other hand, the gauge did come from Harbor Freight, so maybe it does wonder. I know I wonder about it.

funola · #21 10-14-2007, 10:05 AM

KAdams,

What procedure did you use to check the chain stretch? Can you post links to threads you've looked at for it? Both mine has over 200K and I'd like to check the condition of the chain.

Quote:

Originally Posted by KAdams4458

I checked my timing chain stretch this morning, and I'm a little perplexed by my findings.

I could not use a dial gauge, since the camshaft is so screwed up, but I wanted some idea as to the condition if the timing chain before I need to place a parts order. I used the marks on the thrust washer and cam instead.

With the marks aligned perfectly, like so...

I end up seeing this at the crank...

I'd call that 1.5 degrees, so I guess there must be an offset key in place already, since this does not look like a new chain at all...

What are your thoughts? I honestly expected it to be all FUBAR. I never expected this, and I can't comprehend why anyone would go to such lengths to correct cam timing, yet leave a scored and flattened camshaft in there.

KAdams4458 · #22 10-14-2007, 02:30 PM

Quote:

Originally Posted by funola

KAdams,

What procedure did you use to check the chain stretch? Can you post links to threads you've looked at for it? Both mine has over 200K and I'd like to check the condition of the chain.

I used the MB service manual, actually, but there is a pretty good explanation with pictures on this site. It covers both the accurate dial gauge method, and the camshaft index marking method.

Here it is...