I'm doing some work on my 1987 300D and am debating whether or not to remove the intake manifold. I took off that cross-piece in order to remove my fuel injectors, and noticed lots of black sludgy soot in the round end where it connects to all that turbo/egr stuff (getting to the end of my knowledge here). Anyway, the amount of crap in there is scary. Probably 1/2" of gunk. The intake manifold itself is also coated in black, but it appears to be a much thinner coating. This being the case, is it likely that the down-pipes that connect to the head are also thinly coated, or might this be another bottleneck of buildup? I hesitate to pull the thing off because then I'll have to replace the gasket on the head, plus there's an allen screw in the very back that appears to be nearly impossible to reach.

While I've got a thread started... is there a good way to test the glow plugs without having to remove them? Oh, and what size wrench is needed for the bottom-most nut on the ALDA? The ALDA threads I've read say to use channel lock pliars, but I'd rather use a wrench.

Thanks,
Dan

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1987 Mercedes 300D ~200K (Greasecar & Biodiesel)
1993 Ford F-250 7.3 IDI diesel 165K (Biodiesel)
1996 Thomas/International Bus with DT466 engine