Car running hot

[shodown220]

Ok so the past few days i have noticed my temp needle getting way hotter than usual. It usually runs below the "L" of normal. But lately it has been getting way hotter, even above the "N" It also fluctuates a lot. I will be driving the same speed, it will get hot for a few minutes, then cool way down. Then get hot again. Example: It will be running at the "N" and then cool down to the "A" within about 30 seconds. If i get out and put my hand on the intake manifold, it is cool to the touch. The guy i bought it from says he took the thermostat out, so it doesn't have one. I don't even know if that's possible. Oh, and the car is full of coolant. Could a coolant temp sensor maybe be bad? Blown head gasket? Please help!

Edit: I just drove it around the block a few times, it got hot. I got home, put my hand on the intake, cool to the touch. I left it sitting for about an hour (turned off) and checked it again. The needle reads that it cooled back down, but now the intake is very hot. This just doesn't make sense to me....

 

[supersport]

umm u might need a new thermostat, mine fluctuates but not as much as urs does, mine does down when the fan comes on

 

[92inPA]

The first think you need to do is install a thermostat. Make sure you get a rev B model (the one with the jiggle valve). Like this...
jiggle valve
Ford E9DZ8575B
Motorcraft #RT1112

 

[SHOMurph]

Install a thermostat then replace both temp sensors. If your temp sensors are bad then the computer is reading wrong/not at all and your gauge is worthless.

Also check to see if your fan is coming on and working.

Last resort change radiator.

 

[1993MTXSHO]

yeah you need a thermo, thats a good way to mess up an engine. And if its running normal w/o one something is wrong. That was just a patch for a bigger problem most likely.

 

[shodown220]

Ok so i think i fixed it. I talked to my automotive instructor at my college and he looked at it and said he thinks it is just air in the system. After letting some out it seems to be running fine. We were kinda limited on time so i will leave it overnight with the cap off to try and get all the air out. The car had a leaking hose that i just fixed this weekend. And he says that with that hose leaking it is sucking in air, and then when i changed it that it created even more air. So i will just wait and see how she does! I'm going to install a thermostat tomorrow. What is the deal with the "jiggle" valve?

 

[SHOMurph]

Cool. Easy fix!

I would recommend also with any SHO on the road is to change your temp sensors. More than likely if you haven't changed them they are the originals.

If you car runs hot and your gauge sensor is bad then bad things happen.

For minimal dollars its peace of mind.