What should I do... 300SD or SDL - PeachParts Mercedes-Benz Forum

LUVMBDiesels · #10 01-25-2008, 09:14 AM

My 300SD has the usual rust onthe right 1/4 panel over the wheel arch. It also has the beginnings of rust on the drivers door where the stupid plastic cladding holds water. other than that EVERYTHING works from the AC to the tach to the sunroof. Fixed most of it myself, including dropping in what I thought was a good engine from a low mileage W123 two years ago. The original engine in the car had only 140,000, but was not maintained well and developed a rod knock. I pulled it while it was still running and it is up in NY on a stand. (I was going to tear into it but never got around to it) because of this I have a good 617 head, IP, turbo, etc.

It cost me about $900.00 to buy this engine and took a lot longer than I thought to install it. I kept getting held up by dumb things like the oil filter housing needing to be swapped.

Now the thing went screech, clunk and siezed. I had only put about 100k on it with oil changes every 4000 miles and filter changes every 2000mi. I thought that would prevent things like this from happening. I had never even heard of an oil pump chain failing or a pump shaft snapping. Of course this is speculation as I have not been able to do more than look at the outside of the engine down here in WV. It could have snapped the camshaft, crankshaft, or anything else that would not punch through the block. The engine is still full of oil and there are no visible holes wher anything punched through. I am going to bring it over to John Hef soon so he can drop the oil pan and see what is going on.

If the engine can be saved I will gladly fix it. I will be up in NY on the weekends so I can pull any parts of my old engine that John says are broken in the new one. If the engine really is toast, then I do not know what to do. Going out to look for another replacement and then PAYING somebody to do the work down here will be painful. Also, a new engine would still leave me with rust issues.

That being said, I looked at a 1986 SDL last night.

The Good:

Nice paint - no dents, bad scratches, etc
No rust!! I even pulled up the trunk liner...
Windows, memory seats, sunroof work. The window regulators were all recently replaced.
Interior is nicer than my 300SD (all the wood is intact and shiny) no tears in the seats, headliner is nice and smooth
Engine runs smoothly (much smoother than a 5cyl)
Oil pressure looked good
No blowby
Transmission shifts smoothly
Just passed the tough Va inspection
CCU works diverting air to the right vents and altering the temperature from hot to outside temp
Has a power tilt wheel
ABS
Airbag

The Bad:
AC compressor does not engage even in 'def' mode. How much is a new compressor for this car? It is not a GM R4, but looks like a Sanyo or other Japanese compressor (small and aluminum)

The fuel return lines are leaking so badly I did not want to drive the car much. diesel is litteraly visibly seeping from all the lines and down the block. (easy fix)

ABS light comes on, tachometer stops working and ABS funtion cuts out. (easy fix?, ground issues? what could it be?)

The engine will not shut down with the key. (vacuum issue) I did not try to diagnose it, but after dealing with the vaccum switch in the dash of the 300SD I am hoping it is the valve in the IP even if that is a more expensive part

It has the #14 head, but running the car and driving it the temp never got above 85.

Green antifreeze!

Right rear door check is loose (you can hear it creaking when you open/close the door)

Outside temp gauge inoperable (I have one I pulled from a 560SEL) so no biggie.

The Ugly:

It has 289k on the clock!

Rear bumper had lost it's shine. Would the one from the '81 SD fit properly on a 1986 SDL?

Aluminum wheels have lost their clearcoat

Looked by the turbo and I could not tell if it had a trap-ox, did the federal 603 powered cars have that in '86?

The guy wants $2800 for this car. Do you think it is worth the money?
Looking under the hood I realized how much more complex the 603 is over the 617. Wow, electrical connections to the intake, IP,etc...

It drove nicely, shifted smoothly and drove well on a combo of local roads including gravel. I only got it up to 60 so I could not tell if it will run well at 75. It is not fast, but it has a virgin ALDA and will also probably need the turbo boosted to 13psi I am thinking it is probably set at 7~9 like the 617 was at the factory. Have people disabled the EGR/ALR on 603's like you can on the 617? Also does anybody know if the 300SD 14 inch wheels will fit properly on the 300SDL? I am asking because I just bought a set of Blizzaks for the 300SD and I would like to swap them over to the SDL if I buy it.

Thanks for reading a long post...