Engine knock :( (615 and 617) - PeachParts Mercedes-Benz Forum

Raptelan · #1 07-01-2012, 06:52 PM

So now I have two cars with seemingly bad engines...I want to know what it will take to fix them. The most recent is my 1983 200D. A bolt came out of the engine, and it leaked out most of the oil before I noticed a knocking and stopped and found out. I've remedied the problem, filled up with fresh oil, even adjusted the valves, and the engine still sounds absolutely terrible. Same story with my 1982 300CD, except Some different cause I don't remember.

Here's a video so you can hear the sound - what can I do??
YouTube - 200D engine knock

kerry · #2 07-01-2012, 06:59 PM

Unfortunately, I think your engine is toast. No engine can survive a lack of oil for more than a few seconds. If your other engine sounds the same, it's toast too. Time to start looking for used engine.

Raptelan · #3 07-01-2012, 07:25 PM

Quote:

Originally Posted by kerry

Unfortunately, I think your engine is toast. No engine can survive a lack of oil for more than a few seconds. If your other engine sounds the same, it's toast too. Time to start looking for used engine.

615's are extremely rare in the US. What's needed to rebuild?

It was never completely out of oil nor did it overheat, it was just about 2.5 quarts lower than the top fill line.

If it is truly toast, is it safe to beat around in as is for a while?

kerry · #4 07-01-2012, 07:28 PM

Complete rebuild is pretty expensive. You could drive it until it throws a rod. No telling how long it might last.

Raptelan · #5 07-01-2012, 07:42 PM

Quote:

Originally Posted by kerry

Complete rebuild is pretty expensive. You could drive it until it throws a rod. No telling how long it might last.

How much is pretty expensive if I do it myself? Or alternatively, how would I locate a place to do the job right?

79Mercy · #6 07-01-2012, 07:45 PM

Its probably the main and/or rod bearings that took most of the damage. It could have scored the crankshaft, i would personally not run the engine anymore and pull it out. Remove the upper and lower oil pan and have a look at the crank and bearings. Its worth a shot i think

Shortsguy1 · #7 07-01-2012, 11:42 PM

Not sure that the 615 engine qualifies as extremely rare. Someone is selling one on ebay right now. And a guy in Texas is selling a "1971 Mercedes 220D diesel that comes with two very good diesel engines and transmissions for $700 or OBO". Two engines and two transmissions for $700. Plus you get some steel, glass, plastic, and rubber thrown in for free. If only Texas were closer.
Mercedes 220D & extra Diesel Engine

kerry · #8 07-01-2012, 11:50 PM

Sounds like a good deal on those vehicles. I'm thinking a rebuild would run around $3k or so even if you did as much as the work you could yourself.

pawoSD · #9 07-01-2012, 11:57 PM

2.5 qts low for a short period of time shouldn't have destroyed anything I would think.....whats the sump capacity of a 615? On a 617 thats only about 30-35% of the oil....first you said "most of the oil" which to me would mean it lost oil pressure reading, then you said "only 2.5qts".

Which was it? If it lost pressure while running for more than a couple seconds its likely dying.

Shortsguy1 · #10 07-02-2012, 12:04 AM

The OM615 takes 6.5-7.5 liters depending on the model and if you have an air-cooled oil cooler next to the radiator. So 2.5 quarts down doesn't sound instantly catastrophic.

kerry · #11 07-02-2012, 12:26 AM

If enough oil was lost to cause a knock, it had to be more than 2.5 quarts. Where did the oil run out? What bolt came out? If the bolt went into the oil gallery it could have been running on low oil pressure even if there was oil in the system.

Raptelan · #12 07-02-2012, 01:50 AM

2.5 is a guess...that's ABOUT how much I ended up adding to bring it back to level. I would say it definitely wasnt more that 3.5... It never lost pressure. Neither did the 300CD for that matter, it just ended up a couple quarts low. The bolt that went missing is just a short 13mm hex on the right front of the engine, just above the oil pan - I replaced it with one pulled from a 240. While the engine was running, smoke and oil spurted out of the threaded hole. Took me a while to find an only did with the motor running because the radiator fan spread it all over the place. It's pretty sad that a tiny little bolt like that can rattle loose and cause catastrophic engine issues. In any case the problem is what it is and I want to fix it if at all possible. With all due respect I'd like to get an understanding of what it would take to do that rather that being attempted to be talked out of it.

Earlier 60's/70's 615's are quite different, I don't know if the parts I need are the same but all he manifolds and other components are very different. The only W123 615's in the country are imports of a car rarely imported.

The 617 I don't care about as much - I am thinking of swapping a 5.6L M117 into that chassis...But it would be a great learning project and a spare 617 turbo is never a bad thing.

kerry · #13 07-02-2012, 09:03 AM

You'd have to rebuild the engine just like any other rebuild.

mach0415 · #14 07-02-2012, 04:02 PM

Can anyone chime in on vacuum pump noise in the video? I personally have not heard one on the brink of mechanical failure, or if the 615 even has a similar style pump as a 617. This does not seem to be a significant enough loss of oil to merit a failure/damage unless an oil gallery plug was leaking directly and bypassing oil pressure before a rod(s)

Govert · #15 07-02-2012, 04:23 PM

Quote:

Originally Posted by mach0415

Can anyone chime in on vacuum pump noise in the video? I personally have not heard one on the brink of mechanical failure, or if the 615 even has a similar style pump as a 617.

The OM615 from 1980 has more or less the same piston vacuum pump as the Om617.