Good afternoon,
This forum is an amazing resource regarding parts interchange and the differences between various Benz motors of the early 2000s. I am really impressed with the knowledge of the posters here.
I am hoping to have my mechanic swap a low-mileage 2006 Crossfire engine (M112 naturally aspirated) into my 2003 W211 Mercedes E320 (the E320 has a high mileage engine with numerous problems). Crossfire engines are much cheaper and lower mileage than C, E, SLK, or CLK-class engines near me. Supposedly R170 SLK 3.2L engines interchange with my E320 engine, so I suspect that Crossfire engines do too. I want to use as many accessories as possible from the Crossfire engine due to how worn out my E320 motor has become.

I know I need to reuse the ECU from my E320. Can the Crossfire wiring harness be used or must I have the E320 harness swapped over?
Anything else I should warn my mechanic about regarding this engine swap?
And does anyone have recommendations on mechanics in Chicagoland (always good to have a backup plan if mine is unwilling to do the job for some reason)?
Thanks for your assistance in getting my vehicle back on the road.

 

You would need to consult manuals, and compare a 1999-2003 SLK320 (which is very similar to Crossfire) to your own car. Wiring could be the same, but hard to tell for sure. Accessories are probably similar, but power steering pump is likely different. I doubt you'll find much help here on the E class, but benzworld or mbworld might have more knowledge of the R170 -> W211 swap.

 

It is my understanding that an M112 is an M112 and there is no block/basic difference engine-wise. As has been mentioned, the power steering pump (and A/C pump) MIGHT be different.

YOu want to talk to Rudy Compart, he's sure know the answers. But he no longer free-lances, you'd need to go to him thru his current employer, which I am sure can be done.
He is @rcompart here on the forum. <- Click rcompart to send him a message. In my experience, he is the leading technical authority on the Crossfire in North America.