Thread: car runs hot after a few miles if over 70mph

if i cruise slow, drive around town, even idle, or cruise under 70mph, the car wont get hot,

BUT,

after a few miles above 70mph highway, or a few minutes of HAMMERING backroads, the car will get hot and eventually reach max temp, even with the fans turned manually on THE WHOLE TIME!

what say you good people of the SR round table?

fans on a switch and i run them the whole time after it warms up. it does have an aftermarket radiator cap on it, and 230.000 miles.

woo.

You bled the system right? Check water pump, make sure it spins freely by hand (remove belt). Thermostat would be next. Also make sure radiator if flowing well.

Got enough coolant/water? I would check the thermostat first before messing with your water pump. If your water pump was broken your car would be overheating constantly, not just when you drive it hard.

Could be the beginning stages of a sticking thermostat, I lost an engine to that, test the thermostat by dropping it into a pot of boiling water

Well the thing is at 70+ MPH the incoming air should be cooling the engine. Now going 70+ on B14 means you are going around 4k rpm constantly. That's a bit of heat compared to what you would see city driving, even if you gun it you don't stay above 4k rpm for too long.

If it's the thermostat, it would overheat more in the city driving when there is not enough airflow.

It's definitely a good challenge, let us know what you find out!



I would just buy a new one, they cost less then $20.

When my engine to body grounds were bad, my engine temp gauge (as well as my aftermarket gauge) both shot up to insane temps, like around 250. Obviously the real temp of the coolant wasn't that, but the bad grounds were confusing the sensors. This mostly happened on the highway. I took a pair of jumper cables and ran them from the engine to the body and drove like that for a bit and it was all better so I knew where to fix the issue.

ya i know lol. it couldnt just fail like normal so i could know what to replace. it seems like this happens everytime something goes wrong on my car, it fails in some wierd ass way and i cant figure it out

I had a Celica that had those symtoms. Turns out it was the head gasket leaking and pressurizing the coolant system. It only happened when I took it past 4K for extended periods...ie. at the track. Around town it was fine. The weird thing is the oil had no coolant in it and vice-versa, so it was a bitch too diagnose that it had a HG issue.

i vote air bubble..