well, when his light came on the valves started ticking, then the light would go off and the clicking and clunking would stop. he was in the middle of now where and kept driving(stupid). this happened several times over. the truck seemed to have cured itself, then he drove it 150 miles home, and as soon as he got to the last mile, the truck started doing the same thing. the oil light was on and the ticking and clunking sounds were back.
now i don't know where to start. replace the pump, and wonder if he damaged the heads. how exactly would i put a pressure gauge on it?
thanks for the replies