E300D timing chain stretch - Page 2 - PeachParts Mercedes-Benz Forum

Jeremy5848 · #16 06-14-2011, 10:46 AM

Quote:

Originally Posted by Maxbumpo

Very nice tutorial, I've just one addition. I used the same method (6mm bolt) and found that it allowed too much movement of the cam shaft gear, so I could get readings over a range from 1 to 4 degrees.

After a bit of research, I learned that the hole is 6.75mm diameter, so a more accurate reading of the chain stretch is possible if you use the Mercedes special tool (see FSM procedure 05-6010HA, tool is 111 589 03 15 00) or make your own. I think that a 6.5mm drill bit would also be an improvement.

You are right. I read about the correct hole size somewhere but decided to use what I had to get a rough estimate. I had guessed +/- 1 degree of error but your +/- 2 degrees based on actual experiment is a better number. Thanks for that contribution.

Jeremy5848 · #17 06-14-2011, 10:53 AM

Quote:

Originally Posted by Oldwolf

I know my 602 is not the same as your 606 but is the process the same for checking chain stretch?

I suspect that the 602 is the same as the 603, that is, there is a timing mark on the cam and a bump on the front of the #1 bearing cap that you line up. However, in other threads there have been comments that this is a fairly rough procedure and does not produce an accurate measurement. Perhaps that is why Mercedes changed to the 'bolt method' for the 606.

Here's a picture of my 603 taken in 2008; your 602 is probably the same.

rkpatt · #18 11-06-2011, 05:48 PM

The diameter of the "flange" on the camshaft on the OM602, OM603 where the timing mark is located is relatively small. Can one recognize the timing stretch being 4 degrees off checking it this way ?

Quote:

Originally Posted by Jeremy5848

I suspect that the 602 is the same as the 603, that is, there is a timing mark on the cam and a bump on the front of the #1 bearing cap that you line up. However, in other threads there have been comments that this is a fairly rough procedure and does not produce an accurate measurement. Perhaps that is why Mercedes changed to the 'bolt method' for the 606.

Here's a picture of my 603 taken in 2008; your 602 is probably the same.

engatwork · #19 11-06-2011, 06:47 PM

Keep in mind that the bottom bracket that marks tdc can be adjusted a little.

Jeremy5848 · #20 11-06-2011, 06:53 PM

Quote:

Originally Posted by engatwork

Keep in mind that the bottom bracket that marks tdc can be adjusted a little.

Good point, and one never knows whether someone has moved the bracket.

spock505 · #21 04-29-2016, 04:30 PM

I have a slightly puzzling problem with the cam/crank timing on my OM606.910.

It appears impossible to move the chain across the cam sprockets to a position where the crank is at 0 TDC, moving either way by one tooth means it's out by roughly 7 - 9 degrees BTDC or ATDC.

Having done a few of these rebuilds in the past i don't recall seeing this before, perhaps the crank position marker has been moved?

Is it a case of measuring TDC as described above using a needle gauge (sorry, forgot the correct name).

Thanks for any help.

Jeremy5848 · #22 04-29-2016, 11:00 PM

I don't know the range of adjustment in the crank position marker as I've never touched mine. We need to hear from someone with more experience. 7 to 9 degrees sounds like a lot, though. Engine runs OK?

Jeremy

Quote:

Originally Posted by spock505

I have a slightly puzzling problem with the cam/crank timing on my OM606.910.

It appears impossible to move the chain across the cam sprockets to a position where the crank is at 0 TDC, moving either way by one tooth means it's out by roughly 7 - 9 degrees BTDC or ATDC.

Having done a few of these rebuilds in the past i don't recall seeing this before, perhaps the crank position marker has been moved?

Is it a case of measuring TDC as described above using a needle gauge (sorry, forgot the correct name).

Thanks for any help.

spock505 · #23 04-30-2016, 10:39 AM

Hello Jeremy, thanks for the reply.

This morning I started over, removed cam sprocket, chain tensioner and refitted.

It's still out by around 2-3 degress (ATDC) but a lot more acceptable, checked injection pump timing and this is spot on at 14 degrees ADTC - notch level in window.

Hopefully if the injection is spot on the cams are too, even if the crank marker may have moved.

I'll try and get some better pics later, off to do comp test.

spock505 · #24 04-30-2016, 01:58 PM

Finished compression test as follows:

1. 26bar
2. 25bar
3. 22bar
4. 27bar
5. 25bar
6. 27bar

The first test after refitting head ages ago (hasn't gone anywhere since then) showed 28 bar across all cylinders, MB have guidance of 28 - 35 +/- 3 bar for new engines and 18 bar minimum for used engines.

Back to the cam timing, pretty sure it was one tooth out and may have been running like this for sometime. I didn't pay much attention on re-assembly as chain zip tied to sprocket prior to removal.

It would however explain the almost extreme coking around inlets, manifold ect..

Would one tooth out in either direction be enough for a clipped valve seat, or would there be no compression at all?

Current setting:

spock505 · #25 04-30-2016, 05:11 PM

Apologies, just realized hi jacked thread with my compression data. Will fire up a new one if needed.

..btw, using a 6.5mm drill, it fits through the cam housing guide but not the actual sprocket, had to drop down to 6mm as per Jeremy's original guide.