checking timing chain stretch

I want to run the procedure, as I understand it, to check for timing chain stretch on 2.5 190D 1986 mod.
1. Remove valve cover.
2. Rotate engine in normal dir. until timing marks on cam line up.
3. Read the degrees the crankshaft lacks being at TDC.
Questions:
1. Do you use the bolt on front of crankshaft to turn engine over.
2. Can you turn the diesel engine over without releasing the compression in some way.
Please tell me if I have the procedure down right and answer the 2 questions.
Thanks,
Brad

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BRAD FRANCIS
1986 190D 160,000 mi.
SUMNER, TX

BRAD,

Don't know if this is like my other diesels, but I believe that the timing mark on the crankshaft will be past top dead center when the cam mark is aligned. This is, of course, if there is any stretch. Yes, you can turn it over with a ratchet and socket at the crankshaft.

Bring it over this weekend, and let's give it a try. I'll bet with the tool I have we can also get the belt tensioner loosened so that we can change the belt.


By the way, is this REALLY Ashley's car?<g>

Call me,
Larry

Thanks for the info Larry. I believe you're right, if the chain is stretched you would have to move the crankshaft past TDC in order to make the camshaft timing marks line up. Doesn't Benzmac recommend either 5 or 6 degrees as the limit before chain replacement? I'll have to ask Ashley if we can borrow her car long enough for us to play/work on it! Brad

Brad,

I'm going to look at a car in a little bit, and will be late to the house tonight, I'll probably be up and outside early tomorrow, looks like the weather will cooperate this weekend.

I will probably be in about eight tonight, so call me tonight or tomorrow. I'll be around all weekend, so call me and bring it over.

Of course, Ashley could come and do the work while we solve all the world's problems.

Larry

Do use a cup or a bottle as the catalyst for these philosophical discussions?

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Deezel
87 300TDT
150,000 miles

[Benzmac]

On this engine, 3 is the limit. You should re-time the injection pump after you are done. I have been known to do this by ear with the engine warm at idle.

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Benzmac:
1981 280GE SWB
1987 16V
ASE CERTIFIED MASTER AUTO TECHNICIAN
SERVICE MANAGER FOR 14 BAY FACILITY
MERCEDES SPECIALIST 8 YRS
PARTNER IN MERCEDESSHOP.COM

Thanks to Larry Bible and Benzmac. Larry and I put the car up on ramps and pulled the valve covers and low and behold on this car with 160,000 miles, there was not even 1/2 degree stretch. I guess all those good oil changes really pay off. The marks top and bottom were as close as the eye could tell 0 - 0. Thanks again,
Brad

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BRAD FRANCIS
1986 190D 160,000 mi.
SUMNER, TX