Ford V-10 Techs Needed, Diagnos My Erratic Coolant Temp

carringb wrote:
There's no reason 4500 RPM will cause overheating. It's designed to run that fast. I do it, and much faster, for extended pulls up long grades.

As mentioned cavitation will cause pockets of air that get "re-absorbed" when the caviatation stops.

Cavitation is typically caused by the water pump impeller. The bad news is, cavitation also causes excessive wear on the water pump impeller. If this sounds like a downward spiral, it is.

Of course, this is all speculation !