is it my thermostat or my water pump?

[Blaine122300]

Yesterday while driving home from work, I noticed that my temp gauge was a little higher than normal. When I got home, it was just under the "H" mark. I got out and heard rushing water (Overflow tank overflowing). I gots mad and cursed a couple bad words and went to bed. I was just thinking throug it a little, and thougt that maybe my thermostat is stuck closed. I figured that since my heat was HOT in the truck that everything was flowing properly. Also that the hot fluid was getting to the radiator (thus the overflowing overflow tank) that every thing was moving good also. In my simple mind, I deduced that the water pump is good. Has anyone else had this problem, and am I correct in guessing that it is just the thermostat stuck closed? But wait, if it was stuck closed, that would mean that no hot water could get to the radiator. Dang, I'm cornfused. Please help.

Andy

 

[Opera House]

Not the pump

They either work or leak. You just don't hear of impellers flying off or being eaten away. If the thermostat is stuck, you don't get water flowing through the radiator. It is still has presse on it for coolant that is expanding because of heat.....or..... from a head gasket leak. This would force coolant out and create an upper bubble in the engine that causes overheating. If this has been developing over time, it may be time for a new radiator. I would go with the easiest thing first, the thermostat. Be sure to put it in the correct direction.

 

[Blaine122300]

Thanks, I'll do the thermostat and I'll let ya know how it turns out.

Andy

 

[MrShorty]

I had trouble with an overheating engine this summer that was caused by a bad fan clutch.