I have a '79 300D that has a good engine but the body leaves a lot to be desired. Leaks in the rain, floorboards and trunk fill up with water, things cracking and breaking etc. I've found a '82 300D Turbodiesel that has a good body and a blown engine. I was thinking of swapping the engine and using the newer body.

Will this work?

--Craig

If you have both cars side by side this will be a pretty practical swap.

There are several things you should know. To start with the transmission may have a different adapter plate. This plate bolts to the back of the engine and then the transmission bolts to the plate. Before stabbing the donor engine in place remove the adapter plate from the removed engine and mount it on the donor engine.

Next is the a/c compressor. The 79 has it on the upper right of the engine while the later car has a different type compressor on the lower left. The mount holes are in the donor engine block. You will just have to remove the compressor mount from the removed engine and bolt it to the donor engine.

Lastly the two engines have much different glow plug systems. The BEST way to take care of this is to find and purchase the bushings used in what is called the Quick Glow kit. These bushings screw in place of the old loop type glow plugs and allow you to put the pin type glow plugs in their place. You then take the glow plug wiring harness off the removed engine and use it to connect up the pin type glow plugs.

There will be some other small issues but if you have both cars side by side you should be able to figure them all out.

Oh yeah, there is a SMALL difference between the early (80 and prior) starter and the late starter. They will actually interchange and work, but there is a tiny dimensional difference that will put it in a bind or make it too loose, so make sure you keep the starter from the donor engine ON the donor engine.

Good luck,

Thanks Larry, I appreciate the reply. Are any of the other parts interchangeable between the two models, such as window assemblies or seats? or are there just too many changes between 79-81 and 82 123 models?

Your 79 should have the same a/c compressor the GM R4, as the donor car. I have a 79 300d and it has the same compressor as the turbo diesel, and not the York compressor. The trannys are different but will probably bolt up. The main parts that you want to swap should be a drop in and bolt on affair. To do the glow plug wiring up grade then look at the pictorial.
http://dieselgiant.com/mercedesdieselloopglowplugrepair.htm

Its very easy to do.

__________________
1981 300D 147k
1998 VW Jetta Tdi 320k
2001 Dodge Ram 2500 141k
1979 300D 234k (sold)
1984 300D "Astor" 262k(sold)
Mercedes How-To and Repair Pictorials
I love the smell of diesel smoke in my hair

Diesel Giant may very well be right about the compressor, but I know that a 79 240D has a York compressor on the right hand upper portion of the engine. The 300D may not. I think the R4 may have been used on the big bodied cars earlier than on the 123's.

That said, it really doesn't matter anyway, because the wise way to change it out is to unbolt the compressor leaving the lines connected and wire it out of the way while changing the engine, then put it back in place, not using the compressor that is on the donor engine. Now I was able to do that with my 240D when I swapped in an earlier engine but I had an aftermarket a/c. The way the line comes over the top of the engine on the late 300D, it may be difficult to change without blowing the charge, but if I remember correctly I have pulled a 300D engine without blowing the charge. This is one of those things that you will have to play by ear.

As far as other parts, there are MANY parts that will interchange between early and late 123's. In fact most everything outside the engine compartment will. Some interior parts, however, will interchange but will look slightly different. I'm not totally sure about window risers. I think they will but you need to check a parts catalog to know for sure.

Good luck,

Be warned that my '79 has a very different throttle. It appears as though you could just swap the whole linkage (and maybe the valve cover to support it) from the bad engine to the good one.

-Tad

__________________
1995 G320
2003 C230 Kompressor Coupe
2005 ML500
2007 ML350

No the throttle linkage is simple when swapping engine. All of the 123 bodies have a throttle portion on the firewall that twists. You use the rod from the donor engine to slip into the rubber part that twists and it will match everything up to the donor engine.

Good luck,

Cool. I could read about similarities and interchanges between cars for hours. Great when fixing up a car or going to the junk yard. Useful Useful Useful. I think I will make a thread about my 1980 300CD and 1981 300D as I am always finding out what fits and what does not. Or maybe just carry on here.

One great thing I was happy to find yesterday that is more in the vein of this thread was that a Blower Motor I scored off of a 1982 300CD at pullapart fits my 1980 300CD perfectly. And it workS! Not to surprising but I did not check first and it is great to have heat for $15.00

__________________
What Would Rudolph Do?
1975 300D, 1975 240D, 1985 300SD, 1997 300D, 2005 E320 , 2006 Toyota Prius

The door catches (things with 4 allens bolting it to body and that make your door not close easily when the rubber pieces break off) from a 1986 or 1987 or 1989 ??? SD fit the 1980 CD . And are in much better shape generally that the ones off of the older cars .

__________________
What Would Rudolph Do?
1975 300D, 1975 240D, 1985 300SD, 1997 300D, 2005 E320 , 2006 Toyota Prius

Thanks for all the replies. I lost the bid on Ebay for the 1982 300D body with stopped engine when the bids went above $520. I didn't pursue it any farther, because I'm probably not ready to start another project at the moment.

Looks like I'll be selling my 86 300E to fund fixing my 79 300D.