So, looking at these pics - how much timing chain stretch do I have? - PeachParts Mercedes-Benz Forum

bodyart27 · #1 10-25-2003, 07:48 PM

Rotated engine, notch aligned maybe a shade high on cam

bodyart27 · #2 10-25-2003, 07:48 PM

this on revolution one

bodyart27 · #3 10-25-2003, 07:49 PM

as I have read it might make a difference.... so align marks # 2

bodyart27 · #4 10-25-2003, 07:50 PM

reading # 2

bodyart27 · #5 10-25-2003, 07:50 PM

third aligning of mark

bodyart27 · #6 10-25-2003, 07:51 PM

survey says??? What would you call it at? How many degrees?

Stevo · #7 10-25-2003, 08:40 PM

Well, I would say it looks real BAD,

could break and destroy your car. You should sell that car to me cheap and I will dispose of it for you.

I know Leathermang would make you an offer too so I thought I would get my offer in first.

Looks like no more than 2 degrees to me ...... Sweet

engatwork · #8 10-25-2003, 08:47 PM

Something is not right. A stretched chain will not advance the cam which is what the pictures show. I would take a look at a couple things: a) insure that there is no offset key at the cam sprocket and b) see if the timing chain is one tooth off. If the chain stretches the cam mark will line up after TDC or on the other side of the zero mark on the crank.

oh yea - excellent pictures

bodyart27 · #9 10-25-2003, 08:53 PM

engatwork:

where would I look to see if I have an offset key?

The valve cover is still off, so I can go back and take another look.

another stupid question - how am I going to know it is one tooth off?

#10 10-25-2003, 11:52 PM

Quote:

Originally posted by bodyart27
engatwork:

where would I look to see if I have an offset key?
another stupid question - how am I going to know it is one tooth off?

Remove the tensioner spring, it's behind the EGR (i.e. you must remove the EGR if you haven't already

). Loosen the slide rail on the lower left of the sprocket. You don't need to remove it, just enough to provide moving room. Then, you must remove the big nut on the cam and pull off the sprocket (KEEP TENSION ON THE CHAIN AT ALL TIMES!!! If you drop the sprocket or let slack into the chain, you will really be cursing.) Once it is off, pull out the little metal tab stcking out (Sould be near the TDC mark.) If it's perfectly flat on the sides, its normal. If it has one part setting something like .4mm to one side, it's offset.

One toothe is 18* of tming (Crank or cam, I'm not sure). Since it's only 2* advanced, I doubt its off.

engatwork · #11 10-26-2003, 01:23 AM

From what I can tell from here it looks like it is anywhere from around 7 to 12 degrees off with the cam being ahead of the crank.

Judge · #12 10-26-2003, 01:28 AM

What is the cause that the readings are different between say the second and third readings? I see the readings both negative and positive by about 2 degrees, but then why do you say that it is off by 7-12 degrees?

#13 10-26-2003, 07:57 AM

Quote:

Originally posted by engatwork
From what I can tell from here it looks like it is anywhere from around 7 to 12 degrees off with the cam being ahead of the crank.

From those pictures? Naw, if it was it would be past the second beyond the O/T mark. From the pictures it showed: -2,0,+2. About 4* difference. If the engine is ONLY rotated CW there will be no slack in the chain with an accurate reading, if you ever rotate it CCW it will put slack in the chain, making an inaccurate reading AND creating the chance of a tooth skipping when you rotate it CW again. That's why MB manuals are always clear about the rotation of their engines.

leathermang · #14 10-26-2003, 09:43 AM

Some of this changing of readings between rotations may come from the way the tensioner works...
And may not go away until the oil pressure is brought up to working pressure at least once...if you wanted to you could do this without starting the engine...by using an external pump...

engatwork · #15 10-26-2003, 10:04 AM

82-300TD you are absolutely correct. Sorry for the misinterpretation. I had to look at it again this morning. Now, based on my better understanding I believe I would leave it alone if it is running good.
Notice what time I posted that - I was half asleep
thanks

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thanks