I have been looking for a W140 diesel for a while but I don't really have to buy one until I find a good one. I know they are less reliable than some of the older ones but I am too tall for the older (W123/124/126) to be comfortable. I looked at one last weekend and was considering making a low offer but I am not sure I shouldn't look for a better one.

It's a 92 300SD, white with blue interior, the paint is good and other than a couple dents the body is straight. The interior isn't perfect but the seats aren't ripped and the dash isn't cracked, etc. If it was cleaned it would probably look nice. It also starts easily and runs and drives fine, the suspension, brakes, transmission etc all seem normal.

The main issues are:
- One of the oil cooler lines is leaking badly and would need to be replaced, they appear to be NLA so I would have to remove the line and have it repaired.
-The cooling system does not hold pressure, the fan clutch is bad, and part of the fan shroud is missing, but I did drive it around a bit and the temperature gauge stayed normal.
-Speaking of gauges, only the temperature gauge and tach (and I believe the fuel gauge) function, and the ABS light is on. No oil pressure gauge, speedometer (seems to be a common issue with these), glow plug light, or anything else.
-The AC doesn't work, which I would guess is an evaporator leak and would not be worth fixing.
-There are no records of warranty work (engine, wiring, etc) and the engine appears to be original with 220k. It was not low on oil and didn't smoke though.
-Probably the worst issue, there is a quick disconnect on the battery and it was obviously not fully charged. I am not sure whether tracking down an electrical drain on a W140 wouldn't be harder than just buying a different one.
-It also needs tires (they are from 2005) but I would want to do that anyway so not a big deal if the price is right.


I know it's a personal decision as to whether its "worth" buying, but I guess my question is for people who have seen more of these is are they all this bad, or if I could get this one for say $2500 instead of $6500 and fix the worst of the issues would it be as good as they are going to get anymore?

I have only driven one other one (asking $5900) that wasn't really any better than this one is. It's listed for $5k but the seller already mentioned he would take $3k for it, I think even at that price it's too much though.

both are rod bender's i heard. no thanks

__________________
1999 w140, quit voting to old, and to old to fight, a god damned veteran, deutschland deutschland uber alles uber alles in der welt

Unless you know where the cooling system loses pressure, it could be major as in a crack.

__________________
"Rudeness is a weak man's imitation of strength" - Eric Hoffer

I would want to put an OM606 in it in the future, but also wouldn't want to pay much for one that wasn't currently running ok. I think the engines in the 1995 ones are much less of an issue at least, but those are even harder to find.

I'm in California so it's probably unlikely for one of those to have a cracked block or head in that way isn't it? The failed ones I have seen usually have the opposite problem where it holds pressure for days after driving.

There is always much more that needs to be done than what you see expecially if you haven't owned one before. Would you drive it as is with the minimum mechanicals fixed? The guy that bought my 84SD has found lots to address even after I'd done quite a bit.

Plan on all systems needing to be addressed to bring it fully back to specs where it only needs maintenance. You didn't mention a price. I would get a firm price then pressurize the coolant before deciding. It could be simply a hose or a cracked head or head gasket.

__________________
85SD 240K & stopped counting painted, putting bac together. 84SD 180,000. sold to a neighbor and member here but I forget his handle. The 84 is much improved from when I had it. 85TD beginning to repair to DD status. Lots of stuff to do.

I have owned a W126 300SD, 300SDL and a W210 E300D before, but not a W140. I know they will all need a lot of work, but the seller already mentioned accepting $3k and I would only want it for somewhat less (probably $2500 at most).

I would not want it if the battery drain and non working gauges aren't repairable, the other stuff I would be fine with driving it as is until I could deal with it other than the worst of it (cooling system issues, leaking oil cooler line, bad tires). It's hard to find one of these to even look at, so I am not sure if they are all in this condition or not.

There is one listed in LA for $14.5k that the model and interior are no better than this one, it just has half the miles.

W140 owner here. And an owner of two rod benders. Mine had a factory replacement engine and transmission, so very little concerns. Mine has 293k miles. I’d drive it cross country tomorrow.

The issue with the w140 is that it’s big, HEAVY, fairly slow, and complex.

Nice cars, smooth riding. Info is out there to facilitate repair and electrical troubleshooting. The question really is how bad are the electronics. The mechanical systems, especially if you’re planning to do a swap. The cooling system thing concerns me because it puts you in a situation where the car maybe virtually worthless to use/drive. So you have a parked car that you can’t really take and use.

Mine has a good evaporator, a battery drain if I don’t pull rear fuse #6. That does affect tilt steering wheel and a window lift, but it really doesn’t bother me. It was straightforward to find it through the millivolt method.

Question is how much of an appetite you have to do all this work, since it’s a variety of different areas and issues.

I might want to figure out about the evaporator first. Unless you’re good with pulling a dash, that is the job that so think would stop me. You already seem to be onboard with an engine swap.

__________________
Current Diesels:
1981 240D (73K)
1982 300CD (169k)
1985 190D (169k)
1991 350SD (116k)
1991 350SD (206k)
1991 300D (228k)
1996 Dodge Ram CTD (442k)
1996 Dodge Ram CTD (267k)

Past Diesels:
1983 300D (228K), 1985 300D (233K), 1993 300D 2.5T (338k), 1993 300SD (291k)

I know some (most?) of the non-essential electronic stuff and probably the air conditioner will never work if I get one, I'm not too bothered by that. I have read that you have to pull the windshield to remove the dash and a W140 is too big to fit in my garage, so yeah not happening.

Of the issues with this particular one, the main stuff I am not sure about are the battery drain and all the gauges not working (it seems like most of them have this problem though).

Ideally if I get one I could make it reliable enough to get in and drive 400 miles if I wanted, and (with an OM606 swap) have enough power to be in the ~9 second 0-60 range so I could merge onto the freeway without having to worry too much. I have driven a couple stock ones and I know they are way slower than that, but I have daily driven a W126 300SD and 300SDL so I am used to it.

To me, not having functioning ac makes a car a 2-season car at best. And I don’t even live in that hot of a climate.

So I’d consider AC very important.

I’d take my w140 anywhere tomorrow. I would probably care if some of the gauges are disfunctional.

__________________
Current Diesels:
1981 240D (73K)
1982 300CD (169k)
1985 190D (169k)
1991 350SD (116k)
1991 350SD (206k)
1991 300D (228k)
1996 Dodge Ram CTD (442k)
1996 Dodge Ram CTD (267k)

Past Diesels:
1983 300D (228K), 1985 300D (233K), 1993 300D 2.5T (338k), 1993 300SD (291k)

I wouldn't buy a car needing an engine swap unless everything else was very nice. Old cars have plenty that needs fixing that I don't take more unnecessarily. Find something nice with the engine you want.

__________________
85SD 240K & stopped counting painted, putting bac together. 84SD 180,000. sold to a neighbor and member here but I forget his handle. The 84 is much improved from when I had it. 85TD beginning to repair to DD status. Lots of stuff to do.

The whole issue is that I like the OM606 but not the car it comes in, and I like the W140 because it's the only one that isn't too small to be comfortable. I know it's not necessarily a logical ideal, that's partly why I have thought about it for years but never done it. I have a set of nice wheels that would fit a W140 too, too curb damaged to sell but would look fine once on a car.

So, assuming that the car is well sorted otherwise, sounds like it’s time for you to blaze new trails.

Lay out what the fit challenges might be - oil pan, engine mount arms, etc. Then figure out how to check each one, one by one.

Worst case you pull the 603, see some glaring issue, and then do a head gasket job and put it back in.

__________________
Current Diesels:
1981 240D (73K)
1982 300CD (169k)
1985 190D (169k)
1991 350SD (116k)
1991 350SD (206k)
1991 300D (228k)
1996 Dodge Ram CTD (442k)
1996 Dodge Ram CTD (267k)

Past Diesels:
1983 300D (228K), 1985 300D (233K), 1993 300D 2.5T (338k), 1993 300SD (291k)

It has been done before multiple times, I think the main issues are tracking down a euro intercooler, and what to do about a transmission that is strong enough. The 722.3 is marginal even in a stock W140, and I can't find much evidence of the 722.6 standalone controllers actually working at the level of being actually able to drive the car on a trip or something.

Have you gone through the full range of motion on the electric seat adjustment on the w126? I know there is a position that brings the seat much closer to the floor which might cure the height problem.

__________________
'83 SD, 2x '85 SD
You are entitled to your own opinions, you are not entitled to your own facts.

I have owned two, and fixed the seats to work properly, etc. The main issues are that either my head is against the roof (even with the seat all the way down), or I have to lean it back far enough I can barely reach the steering wheel, and my feet are too long (size 14) to fit on the accelerator pedal without turning my foot to the side which gets uncomfortable after a while. The W140 has neither of those problems, and that's honestly the main reason I want one even though it's mostly a worse car otherwise.