I have a 1997 B1500 Van we took on a trip 2 weeks ago and it ran hotter than normal, but never overheating. I am leaning towards flushing the radiator and replacing the thermostat. This is the first time it has gone above normal, the trip was about 240 miles roundtrip, high nineties. Thanks.

 

We've had two recent posters who had their radiators flushed to little or no improvement and wound up replacing them for the final cure

I'd closely inspect the radiator, both sides, and opt for replacement if any of the fins look weak, or dissolve under touch.

I have had one thermostat decide it did not want to fully open before, so that is a possibility. When I removed it and manually opened it, it was stuck, then crunchy.

Considering the entire cooling system holds nearly 4 gallons, if your flushing of the radiator does not cure the problem, consider the cost of an additional 4 gallons of 50/50 mix or 2 of full stength and 3 gallons of distilled H20 and additional labor into the price.

The 2 wire coolant temp sensor on the intake manifold has been known to fail or develop the wrong resistance and cause driveability issues, so replacing it while the system is empty can be good preventative maintenance, and might just help MPG and to pass Smog test, if required in your state.

The one wire sensor is for the dash gauge.

 

Thanks

 

Pop off the bottom RAD hose and drain. Usually, gunk will build up in that location.

Maybe the water pump is going bad too.