Also it starts to overheat after about 10 min of driving.

 

Could be a head gasket, it shouldnt get hot that fast

 

Wouldn't it show water in my oil?

 

Not necessarily. Head gasket can go between the cylinder and cooling jacket, and not affect oil passages at all.

Is it showing hot on the gauge, or just puking antifreeze?

Something isn't adding up here though.....need to reread the thread and think on this one a bit.

 

BTW, what make of thermostat did you put in it?

Did you feel the lower rad hose when it was hot? If it's still cool, then either it's the thermostat, or water pump. If it's hot, it would seem you have circulation, which then rules out the thermostat and pump.

I've recently had an issue with the overtemp switch on one of my trucks, it causes the engine light to come on, but the truck isn't actually overheating.

 

It is showing hot on the gague it is under a lot of pressure on the hose, more than I have seen before. The more I think about it I think it is the head gasket. I blew up two radiators in the last couple of months, (one was repaired with jb weld and the second the radiator shop said was a defect, but it would explain the failure), and it has been running abnormaly warm. Two days ago it started to run very hot and give an overheat light. I thought it was the thermostat but that was not the problem because for the pourpose of diagnosis I removed the thermostat still overheating the upper hose is under a lot of pressure. If it is the head gasket I will probly canibalize the truck and sell what is left for scrap.

 

It was a motorcraft thermostat, I will take it out and run it down the road and check the lower hose

 

Just taught of something, how old are your hoses?


When I was revving my van from the outside, I noticed the top rad hose sucks it's self in when you rev the engine high. Didn't overheat on the way home, even though it was more than a gallon low on coolant, but I wonder if your hoses aren't sucking in and restricting flow?