Diesels w126 SEC om617 turbo

In the beggining it was just a Gen2 c126 with broken V8 M117.965 engine. It took me some time to

find a donor car 1984 300SD.



As my 500SEC did not have A/C I have to migrate complete table from donor car

below you can se the mess…

mess1 mess2 mess3

Not all the parts can be swapped from Gen1 donor,differential is not suitable for Gen2

car and I had to drive at first with 2.24. Later I found proper 2.88. The mask of A/C unit is

luckily compatible. (after CCU is replaced)


non A/C mask


A/C mask

126j 126n

as it was bad quality zebrano and the rest was burlwood I sprayed mine to black



after the dashboard troubles we went to attack engine issues,first we drop

tired om617a with loads of blow by just to see if it fits,I drove like that one month

and oil consumption went to 1.5 L per 100 Km. Nasty.

oldengine1 oldengine2


it took almost 2 months to find proper parts and to overhaul 617a engine

final result was magnificent engine ready to provide another 500K :)


newengine newengine2



Air intake setup I mounted from 1997 300TD and added 1micron CAT huge fuel filter.





2 thoughts on “w126 SEC om617 turbo”

  1. Hi, I am Steve, have a 83 300sd. When you say OVERHAUL the engine, did you have it completely rebuilt? New pistons? If so where did you get pistons? Also, the breather set up you have, I took out my EGR after reming intake/exh, and cleaned out all the gook that the EGR left on the intake ports, and so on.I still have not figured out the breather set up….
    thanks in advance.

  2. Dear Sir,
    Let me introduce myself.
    My name is Sailesh Chander and I live in Malaysia. I have just bought a Mercedes 300GD om617 NA which has been overhauled very well. The car wwas built in 1989
    I admire your work and would be grateful if you could answer my question:

    > I plan to turbocharge it by putting a rear end turbo as there is a lot of space under the car. I read on one of your articles that you turbocharged a om617NA without adjusting the M pump. Am I right? If possible I don’t want to touch the M pump.
    > What boost did you use ? I plan 0.6 bar or 7PSI.
    Would love to hear from you.
    Best Regards

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