Engine Swap? - Page 2 - PeachParts Mercedes-Benz Forum

vstech · #16 09-03-2009, 10:39 AM

yes, it's an interference engine. and yes 40° is WAAAAAAY too much, but before you blow your top and tear into the motor, get the cam mark aligned with the cap mark and see where you're at. I am only familiar with the 617 marks, so I am no help with a 603, sorry. IIRC, 40° is more than 2 teeth off... you should be hitting vavles and unable to rotate the motor with that much slop.

M-Tech · #17 09-03-2009, 01:23 PM

Quote:

Originally Posted by LarryBible

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!

That's my kind of attitude! I'm proposing just that . . . but I'm handicapped in this. I had a lift collapse and crush my hand about a year and a half ago. Reconstructive surgery and a lot of physical therapy and I'm almost "good to go," but there's nothing coming in to pay the bills. Social Security is an option, but I couldn't survive on it. I can wrench it, but I can't buy parts. I need her family to scrape dollars together for parts, and they need to know it's salvageable. That's why (as I posted earlier) I'm exploring all options--from an engine swap to a rebuild.

This car is a gift to my niece, who just lost her '86 Golf diesel to a broken rubber band. Along the way, I need to get something out of it. If it were a running car I'd get the "feel goods" from the gift. Because it isn't, I have to get at least the satisfaction of discovery: this went wrong because of that. I worked for "Mr. Git er Done!" for too many years. Second-guessed by frogs (leaping to conclusions) and parts swappers too many times, and I've got my foot down on this one: Proper and thorough diagnoses.

Up front: this is a car I want, and was looking forward to getting it. I hate to part with it, but I'm doing just that - when I get it running. It goes to a good cause.

Please know that all comments have been and are received well. They are all taken in a good way, and are encouraging. I've lurked on this forum for quite a while . . . just never joined because I worked on other people's cars, and didn't have my own MB. (Well, I did - but that's another story.) I felt that to post a question on a vehicle my shop was getting paid to fix would be unfair. I turn wrenches for a living, and have paid for forum membership (iATN), data systems (Alldata, Mitchell), diagnostic tools, a fortune in special and OEM tools, ASE testing for years, and so forth.

Fixing my own car, though, is different. I'm asking about what I don't know. This forum is filled with owners, for the most part, who genuinely love and respect the engineering put into MB vehicles. I looked at the quality of responses of forum members and found it superb. What I need to know is known by people here.

Thanks again!

Joe

M-Tech · #18 09-03-2009, 01:31 PM

Quote:

Originally Posted by vstech

yes, it's an interference engine. and yes 40° is WAAAAAAY too much, but before you blow your top and tear into the motor, get the cam mark aligned with the cap mark and see where you're at. I am only familiar with the 617 marks, so I am no help with a 603, sorry. IIRC, 40° is more than 2 teeth off... you should be hitting vavles and unable to rotate the motor with that much slop.

Cam marks are probably the same as 617: groove in the cam gear and "boss" strip on the cam bearing caps.

It rotates okay, but with valve timing retarded it might have already done its "hitting" and just not be noisy. Keep in mind, I'm only hand turning; I have no combustion. I don't know what the PO might have done.

Your suggestion is what I had in mind for a "next." I'm trying to go slow and careful to avoid further damage.

Joe

Jeremy5848 · #19 09-03-2009, 04:53 PM

Quote:

Originally Posted by M-Tech

. . . 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?

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. . .

Here is a photocollage of the timing marks in an OM603 engine with no chain stretch. You can see how the marks line up.

I think the PO put in a new timing chain when the cracked head was replaced before I bought the car. I've no idea how many miles are on the new chain but probably very few.

Jeremy

babymog · #20 09-03-2009, 11:22 PM

To be worth buying a $1750 engine, plus tax, plus shipping, plus fluids/filters/belt/seals/gaskets/etc. it would have to be in good condition. In rough condition I have walked away from a driveable '87 300D for $500.

Ready to go, no dents or rust, interior and all parts working without damage nor malfunction it is probably worth $3500-$4500 IMO.

Note that on this car there are other things that can cost money, check them all to be sure that it is worth saving:

Rear suspension and wheel bearings. To have the lower wheel-carrier bushings and wheel bearings replaced by a dealer, about $1500. The parts are significantly less and you can remove the whole shebang and press them in/out. Rear suspension bushings and diff-carrier bushings though can add up.

Air conditioning. The evaporator can be bad, fairly expensive and a big job, also the control unit and the compressor.

Radiator can be close to dead, not a cheap part.

Rust. Mostly the rocker-panels and door bottom crimp, but a leaky trunk seal could cause problems also or a long-time wet floor from parking in tall weeds or a leak could cause rust in the floor (rare). Ordinarily a pretty solid body if not abused.

Body damage.

Be sure that the car is worth saving. If so, I too think that pulling the head to see what you've got is the next step, it should tell you if you need a short-block, a gasket, a whole engine, ... big difference.

Best of luck.

M-Tech · #21 09-04-2009, 12:04 AM

Jeremy - Thank you for the pictures. They're spot on for my "monkey helper," and they're a great visual for me. Jeff - The condition of the body and interior is one of the marvels: it's almost mint. There is a scrape on the driver's door . . . the PO's wife said he did that pulling his boat out of the yard. One rust spot less than a dime which would be covered by trim, normally, at the end of the rear wheel well. Without driving it I wouldn't know about handling. Bushings, bearings, suspension parts . . I have or can fabricate most tools. Parts cost is my concern--but I'm not there yet. For the most part, the car looks to have been well cared for. We will see. I'll keep y'all posted. Joe

vstech · #22 09-04-2009, 10:32 AM

still got the rubber bandless 86? I could use some parts off it.
PM me for info if ya got it. thanks.
that sounds like a good engine swap candidate. the best way to find one is to look for an SDL locally. the wrecking yards should have some, if not craigslist/local paper. the 603 wasn't in the 124's long, but in the 126's, they should be plentiful.