hot B-21000, really

[hOt2000]

Hello, nice site. I recently bought a 87 B2000 from a guy who claimed the water pump was bad and that it heated up. Since then I have replaced water pump, clutch fan, radiator cap, thermostat, and I power flushed the radiator. It is better but still runs too hot and it will overheat after a 20 mile cruise. I don't have water in the crankcase, or oil in the radiator. this really blows my mind I hope someone has the answer to this weird problem. It also appears that water is flowing thru radiator well enough to keep it from heating up. I am out of ideas please help. I also checked timing and pulled the plugs to make sure it wasn't running to lean. Timing is dead nuts, and plugs looked good.

 

[mp3deviant721]

Is your coolant mixture correct?

 

[ForOffRoadDriving]

when it over heats does it actually blow steam and cause the radiator cap to open and vent or is it the temp gauge telling you its too hot?

 

[ForOffRoadDriving]

Is your coolant mixture correct?

good point, if you have anything stronger than a 50/50 mix youre actually hurting the cooling capability - more anifreeze than water does not make it cool better. just a thought since it seems like youve covered all the points i would have suggested.