My '90 300SE has a slight miss at idle. I replaced the plugs 5K ago and they looked good. I remember reading here a while back about looking under the hood in the dark.
I did so tonight and noticed some arcing. The wire from the coil is running between the thermostat housing and a little metal bracket so it touches the housing. I see a constant arc at that point. The wire has a slight cloudy mark where it touches the housing.
I also observed an intermitent, random flash in wires #1,2&3 between where thewire comes out of the valve cover and the spark plug. There are more flashes at #1.
I can't remember what this means. The PO replaced the wires about 30K ago, with what I don't know. The shop that has serviced it uses good quality parts though.
Can I simply re-rout the wire from the coil? Or does that grey cloudy mark mean The wires are shot?
91 300E 120K
90 300SE 275K (sold)
92 BMW 525iM 120K
90 BMW 525iA 175K
85 300D 175K (sold)
84 300SD 245K (sold)