I have a '97 E300 Diesel. The "check engine" light comes on at start up and
the glow plug light stays on a few minutes then goes out. Is there a simple
explanation and/or solution for this? I don't know if this is related, but
at times the glow plug does not come on at all. Unlike my old SD, this car
will not start without that light on, even with a warm engine. Any clues?