I have find out that everything is marked. So i believe that if i well not have to remove IP
there will not be any problems to put it back together.

I still do not have:
For torque specs, you need a manual for your specific engine.
but i hope i well get them soon.

There are two pins holding the upper chain guide. One is also the upper attachment of the belt tensioner spring as in your picture, the other is right at the head/block parting line behind the engine vacuum pump fittings. The one you found has an extension, the other one is recessed. There are several ways to remove the pins: Use an extractor tool like this (my favorite) -



Or a slide hammer like this -



Or use many washers and a bolt to draw out the pins. I believe it's an M5x1 thread, same as the valve cover bolts, but use a stronger bolt than the valve cover bolts.

Don't worry about the chain. It will not disengage from the IP and crank sprockets while the head is off. Worst case is it will fall further than your fingers can reach. Use a hook to pull it up when the head is installed. Don't use a magnet. It might attract debris in the oil and accelerate wear. Likewise, don't use a magnet to remove the valve lifters. Same problem. Try a suction cup such as for grinding valves by hand when that was fashionable.

Sixto
87 300D

Or use many washers and a bolt to draw out the pins

Will be just fine for me for the first.

The second recessed
worries me, because today i have not give jet any attention to it.

And... Thank You for the support.

Tomorrow i should get out pistons, so then i will be finally clear what damage i have to deal with.

Dimensions of the pistons are 89 mm.

The first piston ring (when I pressed it together) is 88,5 mm.
Is this the reason for my problems?
(Or it is just because of deformation pressing it with hand.)
And the first cylinder looks more damaged from second.

Bearings of the crankshaft looks fine to me.

I do not have the documents of this motor but it should be like
from :
WDB60136218140765
2299 ccm 58 KW
601.940
It is that, in the shop, they will ask me for "numbers".

My intentions is to buy piston rings and
seal for head and put it back together.
What is Your opinion?

Attached Thumbnails

       

The ring is installed with a gap to accommodate thermal expansion. Otherwise it would get too tight.

AFAIK to check a piston ring you set it a certain distance into the cylinder and measure the gap. There's a specification for the gap. If the gap is too small (should only happen with new rings), file it wider. If the gap is too big, replace the ring.

The picture of the second cylinder has sharper cross hatching but the first one is also distinct. The difference might be in the lighting and photography rather than actual finish.

There is a prescribed clocking of the rings relative to the piston. The gaps of the top and middle rings should not align. Again, check the manual.

Have a machinist check the cylinder head for cracks if the engine overheated and you have low compression. In the 6 cylinder version of that engine, it is common to find cracks in #4 and #5 cylinder from the exhaust valve seat to intake valve seat and also to the prechamber tip. Machinists can find cracks in the head between the combustion chamber and coolant passages that are difficult or impossible to see with your eyes. such cracks usually expand with heat such as when the engine is running.

Sixto
87 300D

More i think more i am sure that there is nothing wrong with motor blok:cylinder, piston or ring, but i will procede with profesionalist to be sure.

And also i will take the head to scan it, to the profesional.

Thank You

You also need to analyze why the engine overheated. Coolant loss? Belt came off? Head gasket failure?

Sixto
87 300D

In the shop they have told me that i need a Mercedes number for the ring.
Can You help me find it out from the:

WDB60136218140765
2299 ccm 58 KW
601.940

And what do You think ( from the picture ) is the gap to large?

I believe that i know the reason of overheating,..., i will explain it in the next post.

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The dimension of the gab is between 0,55 and 0.60 mm.

The temperature has raised to almost 100 degrees Celsius. While i was not in the van: cleaning parking place from tools. It has happen in a some minutes after test ride. I had put the "new" (210 000 km) motor in my van.I had heard that engine has changed sound but it was to late. The water went out. Yes, i was very disappointed. Bat now it is past. After couple of days of meditation i have find comfort in the decision that I need to install even more stronger motor in my van.

Clamp (just example) in the picture, which seals the top tube of the cooling and engine was not squeezed tightly. I had pressed it to the end as always by feeling in hand but it has blocked before the tube squeezed tightly. But I could not notice that the tube is moving. The clamp was damaged and i did not notice it.

Do not worry about my last question : i have got information whom must i ask tomorrow.

Attached Thumbnails

 

Certain distance into the cylinder and measure the gap. There's a specification for the gap.

I will move ring down the cylinder to see the difference.

an also as i told before:
And also i will take the head to scan it with special tool, to the professional.

I had took my motor head for inspection today. And they had show me signs where
the seal's head broke and the compression had leaking out.

I have forgot to ask how much should gap for new first ring should be.
The nominal value for compression is 21 bar.
So what is the connection between compression and the gap?
Let's presume that conditions of cylinders are irrelevant here. Or that the cylinders are like new.
As i have told my gap is between 0,55-0,60. What compression should i get if i live this
rings. I have doubts because rings looks in good conditions. I will show my ring when i will go to get motor head and ask for opinion, but i would also know what is Your opinion.

Thank you.

That's the gap with a cold engine. Compression spec is for a warm engine. I'm sure your rings are fine.

Sixto
87 300D

They have told me that the engine head was just little
bent and seal was broken so that the compression was leaking between the cylinders.
They assured me that engine head is now all right (they have made some work on it with some machine), so I do not want to give head to pressure test or make X-ray scanning.
I will buy engine head seal ( + air intake and exhaust)over the week and put everything back together next weekend.
With help of the gods.

I hope next weekend will be not so cold.