I put a 91 engine in my 88 190e. My 88 had a single row chain and the 91 engine has a double. I had to use my old manifolds because the O2 sensor is in the manifold on the 91 and there is a pipe that goes from the exhaust manifold to the intake manifold on the 91. I also had to swap out a few sensors in the head to match up with my wiring harness. On the 91 engine the water pump has a temp. sensor, but on my 88 it was in the head so I just matched everything up, and it seems to work fine.

FYI....

About a month or so after i had the engine installed I noticed one of the chain guides was broken, and then after i replaced it , like a week later the plastic cover of my tensioner blade broke and I had to remove the front cover to replace. This was a pretty big project, there was just a lot of stuff to remove and deal with. So you may want to do yourself a favor and pull the front cover(which also requires the oil pan removed or lowered) and replace the chain guides, and tensioner blade. I wish i would have done this with the engine out of the car, before i had everything hooked up and so much more room to work!!

I got my engine from Pat at Potomac German Auto. Give him a call, he's super nice and great to work with!

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1988 190e 2.3 with 91 engine