Hey Guys,

I was driving down the freeway a while ago and discovered I had no heat in the cab. Pulled off at the next exit to check it out, and it stalled from overheating.

I had it towed, let it cool off. Checked the oil-it's clean and at the proper full mark.

Added coolant, tried to start it and blew coolant all over the place, but mostly from the passenger side of the engine. Checked all the freeze plugs, and they are intact. Coolant sprays from the gasket line where the head sits on the block.

I have only put about 8000 miles on this engine since I replaced the head gasket and bolts last winter/spring.

I'm going to start tearing it down to replace everything soon and I was looking for any red flags or tips I should be on the lookout for when I start.

I will be looking for warpage, cracks, etc, but is there anything else I should be looking for?

There were no indications of any problems until this happened. Once I got the timing figured out to get it to run right after I put it all back together, it has run beautifully. I get 28-30 mpg with mixed country and freeway driving. Runs smooth and quiet, until now.

Any suggestions will be appreciated.

Thanks.

Rick

 

Long story short:

I located a good head. Had a machine shop hot tank it, put in new valve guides, re-ground and trued the valves and seats, new seals, new head gasket and bolts, etc....

Finally pull started it on Saturday. Smokes way more than ever before.

Someone I know suggested that the overheat situation has either carboned up the rings causing it to burn oil and blow blue smoke or they have lost their temper. He suggested using an internal engine cleaner (added to the oil) to remove the carbon deposits and free up the rings and reduce or eliminate the smoke.

Elsewhere on another forum, I was told that was a waste of time and I would need to at least re-ring the pistons and hone the cylinders, or do a complete overhaul including new pistons and sleeves, bearings etc......

Has anyone here had a severe overheat of an OM617? If so, what did you have to do to get it working right again?

Anybody have any experience in this situation getting any improvement using something like Seafoam, or AutoRx?

I'm not opposed to the re-ring and honing, but I don't want to take the time for that size of project until this winter if I can put it off. Very busy on the farm this time of year.

Also, I'm looking for some input on high torque starters. In my conversion I have mated my OM617 to a Jeep AX-15 tranny. That required the use of a Jeep starter. I have never been happy with it since I took it out of the box. Just turns over too slow. I'm around diesel engines every day and they start right up because the starter motors are made to handle the high compression. This 1.4kw Jeep starter just doesn't have the power to do it right. Now, since the overheat situation, I cannot get it to start without a little shot of starting fluid, until after it gets good and warm. Even then, if it starts to cool down, it won't do it.

I have found Mean Green starters, and they say they have a high torque starter that will handle it, in the configuration I need, but it is $349.

I have also found a Nippondenso starter that looks like the one from MG, for about half as much. It does say it's for racing gas engines up to 15:1 compression ratio. Obviously it's not rated for the compression ratio of the Benz, but it's much stronger than the 1.4kw Jeep starter made for the 4.0L gas engine I've been using. Like the MG starter, this one is a 4.4:1 gear reduction starter, but I think it has a slightly smaller rated motor.

Thank you for your thoughts, facts, and opinions in advance.

Rick

 

I think I would look for a complete donor engine car, that is running well before you pull the engine. My jeep starter spins good and fast. You can get one with a lifetime warranty, and if it burns up get another