Was offered low miles OM603, tranny, and drive shaft today - PeachParts Mercedes-Benz Forum

cmac2012 · #1 06-02-2021, 05:49 AM

My mechanic buddy, a 603-aholic himself - owns two 350SD models - called me and said he had a motor for my car.

I got some excellent work from him on my van recently so he knows the whole sad story about my SDL. I also got some work from him on my 300D in Oct. '19. I had money but no time and needed to make a 700 mile trip.

This is the Vietnamese guy I've spoken of - I don't want to go all "my Asian friend!" but Vietnam has long had many MB diesels on the streets - he cut his teeth on them as a young man.

I didn't see the car this came out of - he says it had 88,000 on the odo, the body had been beat up by two accidents, but no engine bay damage. He drove it, said the engine is strong. Not sure if this is the trap oxidizer still in place. I didn't think to look for the number on the head, good chance it's a 14.

It's a tough decision. He wants $3K for motor, tranny, and drive shaft, and $1500 to install, including new tranny seals. The SDL is days away from the call to Pick n Pull, no one serious showed interest in saving it. I can't do the work, when I'm out of this place I'd have nowhere to do it.

I got in and assumed the position a while ago. My 300D is a nice car but damn, the SDL is just cool. The seats, the steering wheel feel, it's all good. And that's to say nothing of the greater power, better MPG, and limousine rear legroom. I've got the alum radiator. The old stock radiator could well be what killed my motor, a long stretched out death.

If I go for it I'll take the EGR delete off of my current motor. Brian Carlton and others said it looks like good work to them. I haven't seen others but the welds on mine are good, very good. I'll post a pic later. I can't think of any reason not to resuse that hardware. I've not experienced a 603 with an EGR so my knowledge is limited on that score. Sounds like a potetial, perhaps certain annoyance.

ah-kay · #2 06-02-2021, 11:24 AM

You can get a complete car for $4.5k.

tjts1 · #3 06-02-2021, 11:39 AM

That's steep but the price is fair. There's an active market for these engines to be swapped in all sorts of old trucks and jeeps. I second ah-kay, just buy another car.

Diseasel300 · #4 06-02-2021, 11:58 AM

Third what Ah-Kay and TJ said. Fair price for what it is, but you can get a whole car for roughly what you're gonna pay to install that engine/trans. If it's the original 3.4L from the 350SD it's got a 17 head on it. Expect to change the head gasket soon after it hits 100K, the oil crossover blows out due to the small clearance from the cylinder bore and is a common cause of the "bent rod" issue.

Unless your SDL is in immaculate condition (which it doesn't sound like it is), it's not worth it to put that kind of money into it. They'll eventually go up in value, but that time hasn't arrived yet.

Usaguy · #5 06-02-2021, 01:05 PM

Why not just pay him to change a head gasket on your old car?

He can either pressure test the old head or get a #17 or newer one on.

Should be around $2k for everything.

Even if you do this swap you don't know the state of the gasket on the new engine

cmac2012 · #6 06-02-2021, 02:02 PM

Quote:

Originally Posted by Diseasel300

Third what Ah-Kay and TJ said. Fair price for what it is, but you can get a whole car for roughly what you're gonna pay to install that engine/trans. If it's the original 3.4L from the 350SD it's got a 17 head on it. Expect to change the head gasket soon after it hits 100K, the oil crossover blows out due to the small clearance from the cylinder bore and is a common cause of the "bent rod" issue.

Unless your SDL is in immaculate condition (which it doesn't sound like it is), it's not worth it to put that kind of money into it. They'll eventually go up in value, but that time hasn't arrived yet.

I don't think it's a 350 - I'll see him today, I'll ask him.

My car does have some issues. One of the bigger ones was the serious leaking from the tranny seals. It was something I really wanted to fix, the job had me a bit intimidated. He said he'd renew the seals first, only makes sense.

Finding an SDL with 88K could be tough - he's always been a straight shooter with me, one hopes he is telling the truth there. The motor looks pretty clean, not really proof of anything.

But yeah, I hear you all - that's a lot of money to put into a 360K rig.

I just happened to see the passenger rear door and front quarter panel - the two body parts on mine that need help - in mint condition on a boneyard SEL at Dorris Auto wrecking a couple of weeks ago. They are one of the few remaining indie yards - probably still there, they keep them for a while.

rrgrassi · #7 06-02-2021, 10:43 PM

Why not trade him the 300D for the labor and engine?

cmac2012 · #8 06-03-2021, 03:47 AM

He doesn't like it much, makes disparaging comments about its slowness. Mine was pretty slow early on. Not sure he'd want to take it on as something he could sell to cover his expenses. It still has issues. The odo mostly stopped recently, and this not long after the fuel gauge went dead looking. I say "mostly" because the "you're empty!" warning light still works. I've fixed a lot but the issues keep coming.

Usaguy · #9 06-03-2021, 05:19 AM

Quote:

Originally Posted by cmac2012

He doesn't like it much, makes disparaging comments about its slowness. Mine was pretty slow early on. Not sure he'd want to take it on as something he could sell to cover his expenses. It still has issues. The odo mostly stopped recently, and this not long after the fuel gauge went dead looking. I say "mostly" because the "you're empty!" warning light still works. I've fixed a lot but the issues keep coming.

There's a free fix for the intermittent non working odometer in 123's.

It usually stops working in hot weather because the odo gear starts to spin on the shaft and a fix is to make grooves on the odo shaft so that the gear won't spin on the shaft anymore.

cmac2012 · #10 06-03-2021, 01:58 PM

Quote:

Originally Posted by christuna

There's a free fix for the intermittent non working odometer in 123's.

It usually stops working in hot weather because the odo gear starts to spin on the shaft and a fix is to make grooves on the odo shaft so that the gear won't spin on the shaft anymore.

That's good to know, I'll look into it soon. The BMW E30 had a similar issue. The odo gears were made of a plastic that got soft with age. New gears and you were good to go. The fact of the gas gauge suddenly going dead about the same time is a drag. You can use the trip odometer to gauge your next fillup. I noticed the difficulty when the empty tank light was blinking on and me at only about 200 miles since the last fillup. I'm thinking 'don't take chances' so I filled up and it had room for 18+ gallons. I really, really doubt that I'm suddenly getting 10, 11 mpg. So I started watching it and it does log some miles but then goes still for several miles.

The fix you describe sounds tricky though. I'll research it.

All that said, I'm liking the 300D more all the time. I can relate to Kent. Unless I'm mistaken, his DDs are a 123 wagon and an SDL. I could retire on one of each, I think.

Usaguy · #11 06-03-2021, 03:27 PM

Quote:

Originally Posted by cmac2012

...The fix you describe sounds tricky though. I'll research it.

All that said, I'm liking the 300D more all the time. I can relate to Kent. Unless I'm mistaken, his DDs are a 123 wagon and an SDL. I could retire on one of each, I think.

Here is a good step by step tutorial with pictures:

https://www.ifixit.com/Guide/Repairing+Mercedes+W123+Odometer/25421

Both the 123 and the 126 are great cars. My favorite is a gen 2 126.

cmac2012 · #12 06-04-2021, 02:57 AM

Quote:

Originally Posted by christuna

Here is a good step by step tutorial with pictures:

https://www.ifixit.com/Guide/Repairing+Mercedes+W123+Odometer/25421

Both the 123 and the 126 are great cars. My favorite is a gen 2 126.

What, you mean '86 and after? I know I was impressed with my SDL. My 126 experience is not large. I had an '81 300SD circa '06 or '07 until something went tragically wrong. I thought I was hearing on the death night a hard knock, the sound of play tween the crankshaft and the end of the rod. But who knows, it might have been nailing. God only knows at this point, my experience was so limited that I had no idea. There's a chance that I set it up for failure through an amatuer jail break on the alda. A friend with a couple of 123s with 617s told me they were turned down for emissions reasons. I turned the screw the way he told me, could notice the increase in power right away. But now I gather one can come to grief in that manner.

Who knows, it's over, but I do like the 603 and the 2nd gen seats are really nice. The front seats anyway. My rear seats were so saggy that I packed them full of thick cardboard and styrofoam and some thich rubber matting. Much nicer now.

More to the point, I'll try the odo fix down the road. Would be good, really good to get it operational. I'm thinking that fixing the fuel gauge would be a quicker job so I'll do it first.

Usaguy · #13 06-04-2021, 08:04 AM

Yes 86 and newer 126. They made a lot of changes which I really like.

New seats and door cards were on 89 and newer.

Anyway good luck with your projects!

cmac2012 · #14 06-04-2021, 11:29 AM

Thanks!

Something was changed in the seats in '86. This I discovered as an SDL newbie - I found some nice looking seats from an '84 300SD at Pick n Pull and bought them, less than $100 for the pair, got them home and discovered that the jacks for power and switching were different. That much is surmountable but then I discovered that the '86 seats were firmer, more comfy. I've since seen the innards of such seats. More going on in the structure.

cmac2012 · #15 06-04-2021, 02:09 PM

Speaking of those seats, I pulled the skins, they were in great shape - I think they're leather but they don't have the vibe of high grade leather. Not really sure however they would fit on the post '86 seats. Looks like they would but the newer seats have some extra something going on.