Spark plug wire popping off
I have a 2000 Civic CX, 125,000 mi and the plug wire on the #1 cyl. Frequently pops off. This happens as the engine approaches normal operating temp. If pushed back in place after engine reaches normal temp, it stays in place and runs fine until the next cold start. The occurrence is becoming more frequent which leads me to believe something is in the process of moving toward complete failure.
Plug is tight. Wires are new. I can't figure out how pressure is getting outside of the engine. Any suggestions?