I asked the list a while back about glow plugs (Universal M4-30) and whether they should be a periodic replacement item. They should have been testable in place, but I had trouble getting reliable readings from the meter. So I decided since they were not that expensive ($80 for 4) to just go ahead and replace them so I had a sense of the state of 30 year old glow plugs. It turned out to be a pretty easy job as engine jobs go (about an hour). The only hard part was finding a tool that would grab the circular knurled nuts on top that held the wires on (Vice grips worked). The plugs themselves came out without too much trouble with a standard socket wrench. The old plugs look well used, but not worn out and tested as good with a Volt-ohm meter (about 1 ohms). The new ones made no difference to starting the engine that I could detect. It still takes about 15-30 seconds of glow plug (as the manual recommends) before it starts. So from my experience, this is not an engine part that needs much concern or frequent replacement. Also, since the plus sides are all wired together, my assumption is that if one failed (high resistance), the others would continue to work fine. Dave
S/V Aries 1990 C&C 34+ New London, CT
