memoniz

I would be more inclined to check the water pump. My fins broke off and things went to hell real quick. If you are going to take off the fan, I'd check the pump.

Brandon587

Pumps will corrode or rust over time, at least that's always the problem in my boats. It's not that they really fail most of the time in the sense it just broke, but it's the fines rusting or corroding and breaking. At least that's the problem on my dodge and all my boats water pumps when they fail.

phogroian

Problem resolved, I think.
Thanks to all for being so friendly and helpful. I was fairly sure that I didn't have a blown head gasket because the oil and coolant weren't contaminated, and the engine runs smoothly with even power.
When I pulled the existing radiator (a cheap-looking, single core Modine) it was in fact cruddy, even though I thought it had good flow when I flushed water back and forth through it. I put in a new radiator and cap, the thermostat I already did, and things seem O.K. now... though I will certainly suspect the fan clutch or coolant pump if I have any more cooling issues. I'm going to surmise that the radiator was letting coolant pass only in through certain areas, allowing the motor to overheat, and eventually boiling coolant would force its way into the reserve tank.

centexlimited

So some say open the hood. Why, no reason to unless see something oozing out, steam, smoke.
What will you do about it anyway, stare at it. On today cars and trucks you
don't open the hoods. Or I don't, not opening the hood on my 18, 6 months old, If do see a
message, light, will drive it to the dealership, if will make it, if not warranty can tow it. Electric trucks ++++