73 220d....details!
 

I just picked up a 73 220d with no compression in a few cylinders. What are the details of this engine - model, HP, etc.? I don't know much about the MB diesels outside of the OM617 in my old 85 300D, since departed (but I do still have the prechamber tools, will those fit)? i'm pulling the head soon to see what I ended up with. Hopefully it's just a blown head gasket, or at the worst a cracked head (which someone mentioned is likely for this engine) and the bottom end is ok.

How do I check the oil in the injection pump?

The glow plugs are different, and I believe I see the "salt shaker" on the dash that others have referred to - what does it do?

Thanks!

might want to contact the mercedes classic center to help you get some tech manuals and other info

The engine is a "615" and is the predecessor to the 616 and 617. I don't recall the hp rating but it is around 60 to 65 hp. This engine has a strong bottom end, so it is a reasonable bet the trouble is in the head. The engine idles with manifold vacuum which leads to sucking oil past the valve seals where it cakes on the intake valve poppet back side, and clogs the air flow passage while preventing the valve from seating. When this happens the seats can crack. Not a big deal to have them removed and replaced if the head casting is sound.

Not sure if the prechamber tool is the same or not. Might be. The glow plugs are really from another era and you might be better off updating the system to a parallel wiring rig with pencil style plugs. But if you keep it stock, take care to identify the resistance balancing formed conductors between the glow plugs so you get them back in the right order.

The starting operation is a sequence controlled by a large knob that pulls out of the dash after you energize the system and unlock the steering wheel with the key. First you pull the knob out against a spring load - you will notice the interior light dim if you turn it on, when the glow plugs are energized - and you hold the knob there against the spring load until the salt shaker on the dash glows bright yellowish orange. Once the salt shaker is glowing you pull the knob out further and engage the starter. All the time the starter is running the glow plugs remain energized. Once the engine lights you let go of the knob and it is set to the run position by the spring loading mechanism. Shutting down is accomplished by pushing the knob into the dash all the way.

The rest of the car you will find is very similar to the 240D and 300D. Good luck, Jim

All makes sense except the "resistance balancing formed conductors"...someone has replaced the glow plug wiring with heavy gauge wire and ring connectors, which doesn't sound like what you've described. I do have some pencil plugs left over from my 300D, so I suppose I'll convert it at some point if the engine is salvageable.

Also I should mention that the radiator pressurizes when I try to crank it, so there's something bigger cracked than valves, I'm afraid. But I won't know till I get the head off.

Is there a 115 chassis manual on CD somewhere?

Thanks!

Hi,
-the PC tools(both) will work on your car.
-The oil in the IP is checked by removing the 14mm bolt next to the lift pump-oil must flow out(actually,if not cerviced for a long time,oil/fuel mixture wil appear).You can suck the old oil with a syringe and plastic hose thru the oil fill hole(the cap serves as an air filter at the same time).Use engine oil(appr.200ml. from empty-wait till new oil stops flowing from check hole).Easy job.
-The original setup uses heavy wire glow plug connections-however,when istalling pencil type one has to swap them for 10gauge wire and remove the grounding cable...
http://www.hehlhans.de/bilder/autos/g240/reihe.jpg

http://web.archive.org/web/20041011000859/skinnerbox.steaky.org/Service/Library.html
these .pdf`s decribe actually all om615,616,617 (1968-1985)-even though you`ll find them in the w123 section-you`ll find the engine-related info needed.

The classic centre of MBCA offers service manuals on CD-
http://www.mbusa.com/mercedes/