My 1991 Acura Integra gs is over heating and I have replaced the thermostat and its still over heating?

My 1991 Acura Integra gs is over heating and I have replaced the thermostat and its still over heating what else could it be?|||I assume you mean the coolant is also not mysteriously disappearing, which rules out head gasket failure and a hidden leak (you'd be surprised how common those are.)





The next thing to consider is whether the engine heats up when idling but cools down when going or whether it just gets hot and stays hot. If it cools down when going the radiator fan is not working. The most likely reason is a bad fan (with the engine off and cool, try turning the blades of both fans by hand - lumpy is okay, lots of friction is not) but fan relay trouble is pretty common, too.





If it heats up and stays hot the radiator is the main suspect. When it is hot, carefully feel the upper and lower radiator hoses. If they feel the same, the radiator is not working decently and will have to be replaced. If the lower hose is a lot cooler the radiator is okay but the coolant is not flowing. There have been a few water pump failures in which all the vanes came off the impeller, and in that case the heater will not be putting out much hot air either (be sure to do the radiator test first). Otherwise the thermostat is not opening... I hope it was a genuine Honda/Acura thermostat because aftermarket thermostats are terrible.





In al cases, be sure to use the proper antifreeze - some will cause early water pump failure, as I learned the hard way - and always dilute with purified water. Tap water plugs up radiators very quickly. There is also a bleed nipple on the thermostat housing; open it half a turn until coolant comes out steadily to "burp" the system.|||As a mechanic we are taught to inspect the least expensive part and work yourself up.


Checking the hoses was a good idea but dont just check for leaks, squeeze the hoses and make sure they are not cracking.


if you changed the thermostat then the flow of water is flowing through your engine fine.


Next I would check the radiator. Acura usually has plastic radiators instead of metal so if it has over heated before, then its possible that the radiator is cracked.


Next check the primary (larger than the secondary) and secondary fans. From a cold start warm up your vehicle and check to see if the secondary fan turns on. If not it might be the fan.


Another small thing you can check is the fuse box and make sure the fuses are not blown|||that would be your fan i would replace the fan check the antifreeze but get a new fan and when you replace the fan install a fan switch and when the car starts to get hot turn the switch on and let it run then turn the switch off.|||your rad fan could be broken, you could have sprung a leak some where, you can have bubbles in your rad fluid, or you water pump could be dead|||The water pump or dirty, or a bad mix of, coolant.|||U should have checked your radiator for leaks first,|||could be head gasket is gone does it trow white smoke from the exhaust????