Ignition Coil Housing

Well, this blog entry is a departure from my computer related stuff so far, but still njerdy. Several weeks ago, our 97 Malibu stopping running while my wife was at her mother's house. It would start but run very rough like there was an ignition problem. We had a similar problem which cost us $300-400 about 4 years ago. The first time this happened, I went looking for spark plug wires to check, but there were none. I could not even find the spark plugs which were hidden under a metal cover on top of the engine. Since we needed the car running ASAP, we had to pay for a tow to a mechanic. This time, my mother-in-law was in the hospital and her car was available for my wife to drive while I sorted out the problem.

After my son helped push the car into the garage, it took me a week to get back there and check the engine computer codes which showed "multiple cylinder misfires". It took less than 30 minutes to take the top of the engine off. Underneath was the ignition coil housing shown above which is actually upside down. The four terminals on this housing connect to the spark plugs. Inside the housing are two coils, providing spark for two plugs each. A little checking with an ohm meter showed that there was a short (low resistance) between terminals 1 and 3. Another week of procrastination later, NAPA Auto Parts had a replacement for $72 and about 30 minutes later the car was back in operation.