Guy near me told me I'd I got an E28 he would give the engine out of his wrecked m635. The engine is an M88/3. How much of a pain in the ass are they maintenance wise. I know GPS said the s38 is a pain to deal with just wondering about its similarly powered predecessor.
I don't know much about them, but I've read many times that the timing chain and guides are the weak point (much like that of my little M42), and should be replaced ASAP if you don't know that they have already been recently. I've heard the phrase "time bomb" used regarding the guide rail.
Otherwise, I don't recall hearing about any other issues that are different from any other BMW engine of that generation.
In reply to irish44j:
^^^ this. It is basically a less-developed S38, with all the good and bad things that entails. The chain tensioner design was redesigned with every successive ///M engine and the M88 is known to be the worst of them all; it tensions too slowly on startup and lets the chains slap the guides, wearing them out prematurely. Still a brilliant motor for the right price, though.
Had one in 06 looked almost identical to this.

JtspellS wrote:
Had one in 06 looked almost identical to this.
it's funny, that's exactly what I thought about when I read the title before I read the post :)
Isn't an M883 a 70's dodge used by the military before the CUCV came around?

Is there an easy replacement of the chain tensioner and guide rails to an updated and more reliable version while the engine is out of a car?
You can upgrade the chain tensioner to the one used in the e36 M3. http://www.m5board.com/vbulletin/e34-m5-discussion/128111-s50b32-chain-tensioner-upgrade-s38b36-s38b38.html
and easier to do with the engine out of the car