I have an '87 300D Turbo (A/T) with a worn engine. No-start; cold compression ranges from 220-300 psi. Leakdown test shows bad/worn/stuck rings-worn cylinder sleeves (air comes out through crankcase/timing cover). I've never heard it run. PO had it a short time (from 326K to 329K), said it ran "great," and then just "stopped." He said he heard a "clicking noise" from the engine-- I've determined that this was/is a hanging lifter for exhaust valve #2: it delays opening the valve on cranking, and is intermittent.

["Fuel" in system wasn't diesel; smelled like turpentine or similar. Worst sludging than I've seen in nearly fifty years as a mechanic. Thought rings might be stuck, and worked at removing sludge, but no joy so far.]

Chassis is nearly mint: on rust spot smaller than a dime, one "wheelbarrow" scrape on the driver's door (where PO parked the wheelbarrow to store hay in the "dead" car).

I have access to two fine running '83 300D Turbo Diesels (5 Cylinder A/T) with great needs for chassis repair. Are they good candidates for engine/trans swaps? If so, what should I know about the differences?

Thanks in advance.


Joe

It can be done, but many things such as exhaust, linkages, mounts, driveshaft, hoses, etc. will need to be fabricated. There was never a 616/617 powered 124-body Mercedes so there will be no parts-bin conversion. Starter is on the other side also, so I'm not sure on tunnel clearance, probably fine but ??

The '87 300D is the most fun-to-drive diesel, having the best performance and power-to-weight ratio diesel until the '98 E300 Turbodiesel. If it's really straight, and needs an engine, there's probably someone here who'd like to own it. OM603 engines also show up occasionally as they do get wrecked, and not being worth a lot of money, easily totalled (as well as the SDL cars with the same engine).

My opinion? Look for a good 603, the car really deserves the quiet and power of that engine, put the 61x engines in the 123 body cars.

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Gone to the dark side

- Jeff

Jeff -

Thanks for the quick response. I've got feelers out for a direct replacement . . . exploring all options . . .

This, like most other things we do for family, is a low (no) budget project. I've found a low mileage (under 100K) engine for $1750 delivered, or ship this core out and have it done. I can donate the labor, but no one has money at this time. This is for a niece who's having a baby, and for both safety and class, the MB is a good choice. Her fiance has the two '83's, and would give them up if they would do the job. My contribution is the '87 and the labor of getting it running. (How I got it is another story.)

In case I can't find another bolt-in fit, I have to explore the other options. I'm open to suggestions.

If it were mine, I wouldn't hesitate for a second. I would rebuild the engine that is in there.

Do some reading and searching here, head gaskets are a known failure item but usually long before 329k miles, and the original head castings are known for cracking if overheated.

The 603 engine is basically a very strong and dependable one if not abused.

__________________

Gone to the dark side

- Jeff

Larry -

I wouldn't hesitate - if the cylinders don't measure out of spec. Same issue, though: cost of parts. My niece's momma was talking to me about that possibility just a few minutes ago. I've rebuilt most makes of engine, including Bentleys and other rare birds. I wouldn't be thrown by the MB, but I'd want to know I had resources to draw from.

Mitchell and Alldata fall short in a lot of areas, and other pro techs don't have the kind of knowledge that you have here. Their focus is mainly on bringing home a paycheck, and they're rarely motivated by a love of what makes it tick. I'm generalizing in that, but after my years in the business I think I've earned the ticket for that.

One of the things I like about this site is that there's a good bit of knowledge, including the busted-knuckle kind. Experience is the best teacher; it just isn't always the most cost effective.

rebuild or replace. or both. find a decent replacement and rebuild the original on your own schedule. i am not a fan of engine swaps and the car is a fantastic machine the way it came from the factory. an engine swap will do nothing to improve it.

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punkinfair

It is cost effective if it's someone else's experience, ...

__________________

Gone to the dark side

- Jeff

"It is cost effective if it's someone else's experience, ..."

Which is why I'd ask my questions here.

New thought - (Old thought, new approach.) Checked timing chain. Crank on O deg., cam gear retarded over 40 deg. Enough to drop compression. On rubber band engines with collision heads that would bend valves and/or crack the head. On freewheeling engines it would lower compression significantly, depending on the degree of retardation. Are 603s interference engines?

Leakdown test is inconclusive: after flushing cylinders (soaked overnight, vacuum pump to pull fluid out, then spun with a rag over injector holes) I got much better readings. I'm soaking them again tonight, and will re-test tomorrow.

The question at this point is whether the chain is stretched or jumped a couple of teeth. As I read the valve timing procedure in the MB manual (referenced elsewhere on the forum), basic settings would have to be right first, then measure the drop of the valve (rise of the dial indicator). A 2mm drop at 12 degrees ATDC would be correct - but with a tolerance of 4 degrees. Is that +/- 4 (i.e., 8-16)? Beyond that, the chain is stretched too much.

If the chain jumped teeth, I need to know why and where, and whether or not the injection pump is still timed to the cam, the crank, or neither.

This is an open thread, and I appreciate any input/suggestions.

P.S. Punkinfair: I woould agree with that . . . but the objective here was to get the girl back on the road quickly. If a better (reasonably quick) path opens, I'm for it. I do know that it's a truly beautiful car!

Joe

That is a fair price for a good 603 engine (easy for me to say, not my money ). Just for comparison, however, a complete rebuilt 603 engine from Metric Motors is something like $8000.

In any case, the early 124s are really nice cars and well worth keeping, regardless of how you get the engine fixed. BTW, I trust you didn't pay a lot for it?

Jeremy

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"Buster" in the '95

Our all-Diesel family
1996 E300D (W210) . .338,000 miles Wife's car
2005 E320 CDI . . 113,000 miles My car
Santa Rosa population 176,762 (2022)
Total. . . . . . . . . . . . 627,762
"Oh lord won't you buy me a Mercedes Benz."
-- Janis Joplin, October 1, 1970

That depends on what you meant by "pay." I "house sat" a very small farm for two weeks. They couldn't pay me with money, so they gave me this dead (or sleeping) car. Joe

In that case, you would end up with a nice car for the cost of that engine, less than $2000. I say it's worth it.

__________________

"Buster" in the '95

Our all-Diesel family
1996 E300D (W210) . .338,000 miles Wife's car
2005 E320 CDI . . 113,000 miles My car
Santa Rosa population 176,762 (2022)
Total. . . . . . . . . . . . 627,762
"Oh lord won't you buy me a Mercedes Benz."
-- Janis Joplin, October 1, 1970

You can if this engine until you're blue in the face. There is NO possible way to know the extent of damage or wear in ANY engine until it is disassembled. Take it apart, analyze and rebuild.

If the cylinders are worn, bore it to the next oversize and get a set of pistons and rings. If cylinders mic okay, then rering. Whatever you find wrong, correct it.

Although each engine model has it's own idiosyncrocies (sp?) a factory manual will take care of that.

Just do it!

I really think you need to take the head off and drop the oil pan and really get an idea of the motors shape. And remember ebay and fastlane are your best weapons for an "affordable" engine rebuild (quotes are due to the fact that yes I am aware parts are expensive but much less so if you go and do some searching) anyways good luck! And I agree swapping a 617 series would take a lot of custom cutting and fabrication and it wouldn't be nearly as peppy as the motor that is in there.