i have done a little searching and cant find much, but....i have been overheating on the way to and from work. while the engine is warming up, which is when im still driving in town, everything is fine. but when i get out on the highway, it heats up. really fast, and it goes up to the red if i let it. when i pull over, it cools back down, pretty quickly going down to 220. it will do this 2 or 3 times, then all of a sudden it will drop like a rock to that mark on the guage between 220 and cold. (this is where it normally runs) after that, its fine for the rest of the drive. can anyone tell me what is going on? thanks a lot for any help

 

Sounds like a bad thermostat

 

thanks for the reply, thats what i was thinking too. someone else told me it might be my water pump though. any chance of that? i kind of want a more knowledgeable opinion on that....

 

If the water pump is not leaking out of the weep hole behind the pulley, I wouldn't worry about it. Change the thermostat first and see if it makes a difference.

 

A mechanical pump wont just work and not work, 90% of the time they start to lose a seal and then it leaks out of the weep hole on top of the pump. If your pump was making abnormally loud screetching/grinding noises then it may be the pump, but from your listed problems it sounds like a thermostat going bad. And if it does the same thing with a new stat, it's possible the new one is'nt working proerly either. I've had more than my fair share of brand new, not working properly stats in my time.

 

yeah, i just installed this stat last summer, so that kinda sucks.....but thanks for all the help guys. I think I am just going to go without the stat for a while and see if it quits acting up, then i'll know for sure

 

yeah i would go with a new thermostat.