I apologize for not replying. I have been busy with work and have not had the time to answer posts or take pictures. I appreciate and thank everyone that has contributed to the topic. However, I want to take this post and answer some questions and clarify a few things as well as post some better pictures.

To start of with a few people have mentioned if a total rebuilt is worth it and to assess the value of the vehicle. The car in in near perfect condition. No rust, no body damge, interior is in excellent shape and the car has just been very well taken care of. When I bought the car the previous owner gave me all the receipts to the car. He spend a couple thousand dollars on rebuilding the high pressure pump, repairing the gauge cluster, respraying both front doors because of a minor scratch, new tires, new battery. I myself have put in a great deal of money into the car. Yes it it a 36 year old vehicle and some people might say to just scrap the car because its old. To me the car has more than physical value. It has a special place in my heart and they are just excellent little cars. For me getting rid of the car is not possible. Enough on that.

Moving on to the engine. A few people have mentioned getting a new engine, as well as someone mentioning a om617. I will not be putting a 5 cylinder into the car, as I do not like the 5 cylinders and feel that the 4 cylinder is a superior engine ( just my personal opinion). I live in Washington state and it has gotten quite difficult to find a used om616 engine anywhere. Not to mention the fact that the condition of a used engine is unknown as well as their internals. Many of these used engines have fairly high miles on them and I am just not comfortable putting a used engine in without taking it apart to see its condition. Also, a few people have messaged me and offered me to sell me their used engines. I appreciate the offers but most of them are across the country and shipping would just be too much. However, I will keep the offers in mind as a resort. A few mentioned putting the valves in a valve grinder to see if they are bent. I do not have the means to do so but I will be replacing every single valve as well as the brass guide bushings. Someone mentioned checking the vacuum pump. The pump has been removed and it is functional. As a matter of fact the engine had a similar problem when the previous vacuum pump imploded on the previous owner.

I priced out a rough estimate for parts and it will be a minimum of $500. Right now for me a deciding factor if I do a complete rebuild is if I can find another mode of transportation. If so plans are a complete engine rebuild, manual transmission transplant( I have all the parts except a clutch master), brake rebuild( rebuilding the calipers and new rotors all around), cooling system service( with a citrus flush and mercedes coolant), a/c system rebuilt( have a new compressor just need a expansion valve and drier). If I decide to go that route the parts cost will skyrocket. But, all labor will be done by me.

Now to the pictures. I have tried my best to clean all of the carbon deposits off of the pistons and to clean the cylinder walls. The pictures of the cylinder walls are difficult to see as the walls really have a mirror like finish on them. Let me know if more pictures are needed.

Finally I just want to once again thank everyone for contributing to this post. I am booked with work so I might not be replying often but I will try my best to do so. Also, thank you to the people that provide links for cylinder protrusion and cylinder wall condition. I will try to do those tests when I have the time and report back. I do have a mercedes repair book and I will try to follow it closely. If you have any question or advise feel free to post.

Heres more pictures

From the looks of the pictures I'd say the connecting rods are not bent as at TDC piston protrusion looks the same across all 4.

Post 31 pic 4 and 5, there is a slight cylinder scratch that is in line with the valve notch. I'd call this a piece of carbon that scratched the wall, no big cause for alarm on a high mile motor.

Replacing all valves isn't required unless the stems are worn, pitted faces can be reground. I'd replace the valve guides on the cyl that had valve contact. The valve seats ( in the cylinder head ) will need to be ground as well, all of this is requires the use of an automotive machine shop.

When a chain breaks as was your case, the damage is usually limited to a cylinder or two because the cam stops spinning. When a chain hops a few teeth and keeps going is when valves in all cylinders bend.

Don't try to do too many rebuilds at a time, a engine rebuild / trans change / AC repair is a major project and I've seen too many cars get taken apart never to go again. Repair the engine then move on to another project.

Mercedes source is in Bellingham, WA they might
be able to help you with parts, info and hands on
if needed.
Yes, everyone here is very helpful but having a
phisical place to go to when you're stuck or for
a hard to find part is always helpful too.

Louis

Nikkondy, I can relate to wanting to fix an old car to peak condition go for it!!!

Have done this twice with no bent valves either time. You already may be aware that the valve seats should be ground so the head needs to be worked on by a machinist. If you want to, most if not all of the valves may be within spec and be reground by the same machinist. Others may disagree but I VERY lightly ground new valves anyway to make sure they are correct before installation. Your call but all new valves may not gain anything.

Did you decide whether or not to pull pistons? I used first repair size pistons 0.5 MM and had the block bored accordingly, no sleeve replacement. Take note that the number one piston clearance is slightly different than 2-4 if boring is done.

The crank was perfect with approx 140K on the odometer.

Good luck!!!

With that in mind I applaud that you want to do a proper job.

It seems to me that if you are such a fan of the car someone else out there might be too. Although it is a arguably a bit early to start such considerations perhaps matching numbers means something to you too?

It is difficult to tell from the pictures - it could be a lighting / flash issue - but shady patches on cylinder walls usually means uneven wear. "Seeing as you have it in bits" I'd be borrowing a bore micrometer to check.