Hi guys/
I replaced my plugs today and gave an oil chavge.Went for test drive and temp gage went almost all the way hot then back to normal.
I dont think i could have done anything to cause that:just replacing plugs.It does this when starting cold.if engine is warm then just stays normal.Anyone else experince this?
Truck runs fine and no check engine.Used auto lite double platnums.

 

any one??? was thinking changing tstat.But could it be fan clutch?

 

your thermostat stickin?