Quick question for the forum. So my 1982 300 TD engine finally gave gave out on me at 461,000 miles. Looks like it was a timing chain issue. Luckily I was able to buy a 1984 300 TD wagon with the same exact motor but with only 230,000 miles on it!

Here's the question. There are a few things that appear to be different, and when I say "different" I'm basically referring to maybe a different vacuum connection or a different electrical wire connection. The parts in question are;

- The Turbo
- The Injection Pump
- The Thermostat Housing

Is it safe to assume that I can just install the turbo, the injection pump, and the thermostat housing from my old motor? This would make my life way easier as I could just plug everything back in to the existing wiring and vacuum system. If I have to move the wiring and the various vacuum components from the 1984 parts car over to my 1982 car, things are going to get pretty confusing.

Thanks!

If they're both an OM617.952 you should have no issues. If I recall, the emissions related stuff began in in 85 in California, most other cars are Federal and mostly the same vacuum setup. Did the 84 motor not come with those parts? I would suggest using all the lower mileage stuff you can and modify what you need to get it to work.

You've only got 3 areas to think about with the vacuum system:
- ERG - can be bypassed or removed if you can't hook it up like factory.
- Transmission - As long as you have vacuum going to the VCV valve on the injection pump, then to the transmission with the appropriate Y fitting, damper, and restrictor you're set.
- Accessories - Just connect from vacuum to the hoses going into the firewall

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1983 300TD
1985 300D
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Don't connect the electrical connector on the 84 injection pump, its not necessary. The turbo may be a different brand between the two engines. KKK and Garrett were the two brands, I believe. Both are interchangeable if the outlets are pointed the same way. The vacuum connections on the thermo housing are completely unnecessary. They are for EGR.

How this goes .

A friend of mine had the same situation, his engine grenaded so he bought a rusted out wagon and swapped the engine over complete, no modifications necessary, last thing I knew the car was still purring along almost ten years later .

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-Nate
1982 240D 408,XXX miles
Ignorance is the mother of suspicion and fear is the father

I did then what I knew how to do ~ now that I know better I do better

The '84 engine may have the KKK turbo - ID'd by a round, finned waste gate housing pointing perpendicular to the car out toward the fender, instead of a Garrett ("AiResearch" cast into the compressor housing) which was on most of the cars. It may also be just the Air Recirculation Valve that came on the later Garretts. The ARV can be left disconnected, it's a normally-closed setup. The only difference on the IP should be the Rack Position Sensor, a square sensor on the block-side of the pump - it can also just be left disconnected, or if your old engine was running particularly well before it kaboom-ed, you may even swap your original pump over to avoid any headaches with the more unknown pump. I hope you'll save the head off your old engine unless it's busted up too bad from the failure - wagon heads are rare and there'll only be more demand, and less supply, in the future!

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'82 300CD
"Pearl", the very first turbo diesel 123 coupe
Totaled 11/23/18, rebuild in progress.
'85 300TD, "Artemis".
'78 300D euro, "Ol' Red", mostly retired.
'85 300D, "Gandalf".

Thank you! You just made my day. One more question. The transmission on the new motor has an electrical sensor attached to the front of the bell housing, the old motor did not. The transmissions look identical aside from the sensor. So, I'm assuming I can just go ahead and cut the wire and just leave the sensor element attached (just to keep the hole plugged up!)

Thanks for all the replies everyone! You all were a big help!

Cool! Thank you! So I can just go ahead and cut the wire that's connected to the electrical gizmo on the side of the IP?