Warning on Autolite Spark Plugs

New 4/6/05

I learned something interesting this week about our spark plugs. When I first bought my car and had the cams welded I had Autolite AP764 plugs put in because that was all I could find locally. Lately I've been having some engine roughness and decided to replace the rear coils and the plugs - this time with Motorcraft. When I took out the old plugs and compared them to the Motorcraft plugs I realized that the Autolite plugs only had half the thread depth.

I could see carbon past the threads on some of the Autolite plugs and one had been blowing up past the coil even though the plug seemed to be in tight.

With these replaced and the new IMRC, my car now runs like it used to.

Richard Wills
99 TR

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