Exhaust manifolds were a nice combination of carbon and rust:
The insides got the Permatex + wire wheel treatment. When they were clean I took a die grinder to the rough casting and smoothed it out especially around the recesses for the studs; they seemed unnecessarily restrictive. Just a little OCD folks, nothing to see here. Really nothing, since I seem to have lost a lot of my pics. But seriously, cast iron headers . . . what are we, cavemen?
I cleaned up the flange surfaces as best I could, they looked like medium-altitude shots of the surface of Mars. I ordered new downpipe gaskets but reused the manifold-->head gaskets after cutting off the disintegrating heat shields. I was going to ceramic coat the headers inside and out but ended up skipping that step. Not normally something that people do with stock cast headers, but it would only cost a few bucks to do it myself (Techline Cil-Gen Satin Black + airbrush). In fact I intended to blast and paint every part I had to remove, but time was becoming a factor, and as always I'd researched just a little too much . . . enough to Start Getting Ideas. There's a reason my gf has standing orders to taser me if she catches me cackling maniacally while reading a project-related forum.
Back to the work in progress:
The entire area behind the valve cover baffle was a solid mass of sludge. If I'd had any idea how much work cleaning it would be I would've just removed the baffle, hosed it out, and riveted it back on.
By this time I'd dealt with (or at least identified) all the factors contributing to the idle problem, and I managed to remember that replacing the timing belt was the whole point of this exercise. The front of the engine was in the same sad shape as the rest:
The cam seal, didn't:
Beauty shot of the thermostat housing mount:
And this little beauty . . . it was packed full of sludge, and not much fun at all to clean out. I had no idea what it was, but figured it must be important since the BMW logo was cast into the bolt head. Let's just say that by the time I figured it out, I knew my way around the realoem diagrams.