Ok im at a loss what would cause a spark plug to blow out. The threade apperar to be ok tghis has happened twice in the last month any help would be great Thanks and Prayers Ray

[This message has been edited by rlinn84 (edited 06-05-2006).]

usually rust. I would guess it is one of the foward plugs? or you got a bad batch. the only thing holding the ceramic in the center is that slight crimp all the way around at the metal base. it is very thin, and will rust out fairly quickly. then normal pressures will work the piece loose and pop goes the spark plug!
This is fairly common on marine motors that have leaks in the water cooled exhaust manifold, drips on the plug and rots that crimp.

What brand are they? ...Especially Champion's have the habit to blow out, even when new.....NGK's are the best imo

Hey Ray, Which car is it ? Yours or your Son`s ?

mine (well the one that will be my daughters in two weeks ) i picked up an 84 se that we will be swaping the motor from the 85 into as the 84 is in better shaap and has power locks and windows and ac that the 85 didnt have will still be painting it green though. will send pics when we get them Ray

Ray, Thats a 4cylinder your popping plugs with. Your saying the entire/whole plug is coming out, or just the top ceramic part?