i jus bought a 90 ls integra and i noticed the needle starts going real high even driving on the highvvay so i called the kid and it said turn the heat on i did and the needle vvent back dovvn to cool anyone have any ideas vvhat it can be:ok:
THermostat
check your thermostat…most likly would be the problem.
I was actually just watching two-guys garage and they were talking about those exact symtoms eg. running hot while freeway driving, and heater will counteract this problem.
I relates to your coolant system and corrosion. They recommended you inspect and replace radiactor and all fitting for corrosion
also I saw this today http://www.g2ic.com/forums/showthread.php?s=&threadid=36941
scroll down and look at cooling systems
First of all, make sure your coolant level is good. Just because you pop the cap and there is coolant up there doesn’t mean its full. If when flushing and renewing coolant you don’t leave the fan running on hot, you can get air pockets in the coolant system. Try this: take the cap off and start your car. Turn the heat on full blast, and let your car warm up to normal operating temp. After this time check the level again. If its low, top it off, and make sure your reservoir has some coolant in it.
As mentioned before, the next thing to do is replace your thermostat. You’ll need the offset one from NAPA, Schuck’s, wherever.
While you’re at it, you might as well buy a new radiator cap as that can cause minor problems/inconveniences.
HTH
-Kevin