Engine Compatibility 76 240D vs. 79 240D
 

Hi, I'm trying to help a "starving college kid" son of a good friend of mine. He has a 79 240D Automatic which just threw a rod, unfortunately. We have located a '76 240D at a shop with what is supposed to be a good engine, but the shop is giving mixed messages as to whether the engine from the 76 will fit the 79.

Can you tell me what I should check/note/look for on the '76 to determine whether it's swappable? We can note VIN's, take photos, or whatever is needed.

Thanks in advance, my experience is all with the 606 in my '95, but my friends look at me as the "MB diesel expert"... I have to try to live up to their expectations!

Rgds,
Chris W.
'95 E300D, 264K

I'm not sure of the year of most changes. the engines are pretty much identical internally but the location of the oil filter, ac compressor and other things may be very different. You just have to take an inventory of the differences and see if its worth the work to swap it.

Of course finding the same year motor is always best.

Good luck.

Tom W

the '76 would be a 115 chassis and the '79 is a 123. They are not directly compatible. Since there is an endless supply of 123 chassis motors around for sale I would say it is not worth the hassle of swapping them. You'd have an easier time swapping a turbo 5 cylinder into it and that would be a great upgrade. I know where there is an engine for sale for $400.

Having said that, where's the shop with the good W115 motor? I could probably put it to use in the near future in my '74 :-)

Hi Doc,
Far be it for me to question your knowledge of 123's but a brief bit of research I did shows that there were 123 bodied 240D models in 1976 - but you're right that the research shows that in North America they started in 1977. I guess it's possible this is some rare import, but I doubt it.

It's also possible that the shop doesn't know the precise year, too.

When I eyeball the car I'll know if it's a 115 or a 123.

Rgds,
Chris W.

Right you are, in europe there was a 1976 240D in the W123 I think but not in the USA...I assumed you were speaking of a US Spec '76 240D in which case it would be a W115. Obviously if it is a W123 chassis that is a different story and the engine is probably a drop in replacement.