coolant temp running high?

[Jcanapa]

I recently rebuilt my engine and so far I have about 900 miles on it. At first my coolant temp was pretty normal when I was just driving around town. It was in the middle. When I'd got on the freeway at 65-70 mph it would be an 1/8 inch below the hot then when I'd slow down and drive 35 mph it would drop down. I drained a gallon and added more water and a half of a bottle of water wetter. Now when Im on the freeway its running about 2/3 of the way on the gauge. Id think in the city it would be more likely to run hotter than on the freeway. I'm kinda stumped on this. Also sometimes when I hammer on the car it goes up too. I did check the temp with it 2/3 of the way. The bottom hose was about 155 degrees or so and the top hose was about 180 or so. The head area was around 195 to 210 or so depending on where I checked the temp.

Any help would be great.

 

[DSMcrazy3]

Could be a faulty thermostat. They're cheap and with problems going on with the coolant system, I would swap it out whether it needs it or not. Check for leaves or any build up before the radiator, that can also cause these types of problems.

 

[dr1665]

Could be a faulty thermostat. They're cheap and with problems going on with the coolant system, I would swap it out whether it needs it or not. Check for leaves or any build up before the radiator, that can also cause these types of problems.

I agree with this suggestion. Could just be that the old tStat is sticking from time to time.

 

[E-CLIPS97]

What if temp gauge is LOW. Not to hi-jack thread, but my temp gauge only goes up a little above cold, even though I drive for 20 minutes at 80mph AFTER letting the car idle for 5 minutes....

 

[arash15]

throw a datalogger on and see what kind of coolant temps you are getting when the needle is at its "operating temp". I had to do this on my 2g and "recalibrate" the temp sensor so the needle reads correctly.

 

[markGSX]

What if temp gauge is LOW. Not to hi-jack thread, but my temp gauge only goes up a little above cold, even though I drive for 20 minutes at 80mph AFTER letting the car idle for 5 minutes....

that would be your thermostat stuck open. the original poster probably has it stuck closed, not allowing flow to the radiator.

 

[opie1]

i had the same problem and it was a piece of crap thermostat. i would get your colling system flushed also, just a suggestion

 

[Shadow98]

I had the same problem, until I replaced the tremostats. Everything is running good now.

 

[Injenpwr]

that would be your thermostat stuck open. the original poster probably has it stuck closed, not allowing flow to the radiator.

I too had this problem with my thermostat being stuck open. It was broken in such a mangled way it looked like a pretzel.
When I first read the poster's problem, I assumed that since he said he rebuilt his engine, that also inclued updating his colling system as well, but I could have misinterpretated? I wonder if he found the problem out yet... if it was his thermostat?