Dead Cylinder

Hi, My 1985 Tercel (2dr cpe - SOHC Carbureted) threw the spark plug out of the #3 cylinder while on the freeway. The car starts and runs without any obviously abnormal sounds. Compression shows all cylinders at about 160 lbs, while the # 3 cylinder shows only 20 lbs. Any ideas as to what went wrong, and how major the repairs might be would be greatly appreciated. Thanks.

does the 3ed cylender have tons of oil in it? And do you have a plug in the 3ed cylender now? or did it strip out?

No, no oil in it. Also, the plug just backed itself out....twice. THe first time I thought maybe it was loose since I hadn't replaced the plugs in a while. Unfortunately, it did it again shortly after re-seating all the plugs. Basically, it looks and sounds normal to me, other than I have no compression in that cylinder.

And a correction to my first post, it is an 1989 Tercel - 3E engine.

Thanks

any loss in power? Sounds like a valve problem.