diesel swap worthwhile?
 

I found a almost perfect 1985 380se, black on black and it looks like it rolled off the showroom floor. the only problem is that the engine is really tired.. i was thinking of swapping in a om617 from my 300sd parts car into it.. the guys wants 2k for the 380se. Would this swap be too difficult?

no comments? I mean we all know that this is gonna be a money pit but I just wanted to get someones comment if they have done this.. can a home mechanic do this?

Its doable in a weekend. Beware the tranny will probably have to go as well.

And the diff as well...

And the instrument cluster...

If you have a complete parts car sitting next to it the swap should be a straight forward project. Since they are the same car.

But its not nearly as simple as removing the M116 and putting the 617 in its place, MB changed a bit.

I would expect to do the engine, trans, and diff. Along with all the diesel controls, oil cooler and radiator, lots of vacuum lines, etc.

I wouldn't be surprised if you have to change the ignition, shifter, front springs, AC lines, and some heater hoses to make the climate control work.

The drive shaft may even be different.

Done this, several times, Yes doable in a weekend if you are a decent to good wrench, dont have to change the cluster(no reason to), dont have to change diff. yes to rad, oil cooler, vacuum lines are so simple its not worth discussing. Ignition switch should be swapped so you can have the proper shutoff.

on a 380 SE, the driveshafts will be the same lenght. shifter is the same.

trust me on this one the 2.47 diff suits the 617, i averaged 28 MPG over 60K miles on 85 500 SEL with a 83 300 SD motor.

its worthwhile, Ive done it 3 times.

2 points to note, on my swap the tach did not work, I didnt swap clusters and wire it up,

second point, its bolt in except one of your engine shocks will be on the wrong side, and will not have a mount on the frame for it, I left mine off.

I didnt change front springs, and the wiring for a diesel is very straight forward.

Engine swap on a W124
 

I swapped a gas 103 engine for a Nissan RD28 diesel engine. Took a month. However, swapping a Mercedes for another would be a lot easier.
For instance, your present VDO tach may work without modification with the diesel engine.

The exhaust manifold may be in the same side. Mine was in the opposite site, as well as the radiator input and output.

The electric system will be easy for an electrician.
Air filter: would be necessary to adapt one.
Probaly you will need to put new shock absorbers as I had. New engine will be a little heavier, old shock absorbers will die. Your car will (bend?) don´t know the word in english.

Good luck !

No it won't. Diesel tachs only work with diesels. And gas ones only with gassers. I know this for a fact.

Its better to just swap clusters...(which is super easy) so why not?

I'd do it if the car was really nice. At this point if I find an excellent W126 in need of a motor I might consider a swap myself....the rust is becoming unmanageable. :o

AAAAnd....
 

Be ready to change out the ignition switch so you won't have to open the hood to shut her off everytime.

Regards

Run-Em

2000 is more than I probably would pay for a v8 with a tired motor.

It would have to be absolutely showroom condition other than the motor to be worth that, I think.

Tom W

2K is a little more than I think I would go unless the rest of the car is really good. I went about 2k(after adding in transportation back here) BUT, I already had a pulled engine for my 86 SDL. The care had about 178K on it, sightly worn, no rust, and otherwise, pretty good shape and I had recent records.
I seemed to luck out with the replacement engine also. A slight misfortune (cracked oil pan) let us check out the bottom end, and it appears that it was recently rebuilt.
It does run real good.

Bear in mind, I did not have to change out any gas related items either.

... how "tired" is the gas motor? does it blow blue smoke? any noises in the motor? are you planning to drive the gasser much before you switch? if the car runs well, but is just a bit on the weak side, the seller has no compunction to lower the price, simply due to you wanting to put in a diesel... pristine vehicles with weak but running well motors still have decent value. the gasser motor would have some value too. Oh, and I don't think you have to change the transmission.

yeah the transmissions between a OM617 and M116 are differnt, will not bolt up.

There is no reason not to change the cluster, On my swaps, I left the gas cluster, since that is the mileage on the vehicle. I didnt care about the tach to much, so I just left it disconnected.