I’m miffed. I filled the block through the thermostat housing after changing the thermostat and both temp sensors. I’ve tried multiple times to bleed this system, I still need to try drilling a hole in the thermostat, and then i’m going to have to assume it’s the water pump. This time around, the thermostat didn’t even open, and coolant was boiling out of the radiator cap overheating (off to bleed system). once I turned the van off the thermostat opened, started it back up and still wouldn’t cycle right. Heater wasn’t blowing hot. At this point i’m looking for any extra insight. Chatgpt has gotten me this far, but my driveway is still covered in coolant and i’m going to blow a headgasket if I don’t learn when to quit.

 

Is the fan clutch engaging when the engine is hot? The fan may be spinning but that doesn’t mean the clutch is engaged.

2 ways to check:

1) With the engine warm and off, try spinning the fan manually - it shouldn’t spin freely at all and provide significant resistance to turning (quits spinning as soon as you let go).

Also rock the fan front to back (relative to radiator) to check for play in the clutch - any movement means it’s bad.

2) With the engine running the fan should be pulling enough air through the radiator & condenser to pull a sheet of paper up against the grill and hold it there.

I would also advise making sure the radiator and condenser fins are clean - mild pressure from the grille side or a garden hose & sprayer from the engine side should clear them out.