Hi

The e36 325 engine in the viento has been idling roughly, and I've had a fault code 16: "Camshaft ignition sensor or ignition pulse. Check spark plugs, coil packs and camshaft position sensor"

The plugs were new, so I've tried everything else (to no avail), but came to pulling them last night. Found that most were a (normal?) browny dusty colour, but cylinders 1 and 5 were very white.

Presumably this means these cylinders are running lean and therefore hot? If so, what could cause this? I'm thinking either vacuum leak on the inlets for these cylinders, or clogged injectors?
The exhaust headers for these two do get hot at idle, so something's going right...

Cheers!

If all the other cylinders are good, then probably a vacuum leak, or manky injectors. The headers will get hot if its running lean, even more so than normal, since a lean engine/cylinder runs hotter than normal. Do you have a common air filter or one for each cylinder? Could be two are clogged if they're seperate.

Common filter.
Can't see how I'd get a vacuum leak on just those two, but have splashed £4 on 2 new inlet / head seals to check tonight.
I've got another one of these engines, so I think I'll be swapping a few injectors round if the seals are OK.
Am I right in thinking this cold be causing the rough idling?

Could do yes. If two run lean, they unbalance things a little, and could upset the idle.