1988 e150 van 5.0 liter overheats, even tho I have flushed system twice, installed new thermostat, water pump and radiator. Coolant doesn’t circulate thru bottom radiator hose, and engine gets hot in less than 5 minutes just idleing. Going nuts. Please help!
You probably have an air pocket. Flush it again.
The engine may have a blown head gasket.
To find out, when the engine is cold remove the radiator cap.
Start the engine, and while it’s idling watch the coolant in the radiator.
If bubbles begin to form in the coolant, that’s an indication of a blown head gasket.
Tester
If it overheats after idling for 5 minutes after a cold start a bad head gasket is likely.
Are you ABSOLUTELY certain you installed the correct water pump?
There are 2 pumps which are interchangeable. One uses a V-belt and the other serpentine. The pumps rotate in opposite directions.
Install a serpentine pulley on a V-belt pump and it will rotate backwards. Same goes for the reverse.
But I thought the engine was overheating in exactly the same manner prior to installing all those new parts. But if not that is a likely cause. I seem to recall that many Ford water pump impellers were directional.