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So a few months ago, my radiator gauge started to run a little hot, and I thought nothing of it. Then it kept happening, running hotter (eventually at and above the H) and I stopped driving for awhile. Then I asked my brother and he said it could be a number of things, but we started off with the simple stuff and replaced my thermostat. That worked for a few days and then it started to run hot again. He has suggested replacing the fan switch relay and the water pump. But I have the feeling that this may not be a mechanical problem, that maybe my gauge is just messing up because it will go up to the H, and then come back down to normal, and slowly oscilate until I turn off the car, AND my radiator isn't leaking and it's full of coolant. So if it sounds familiar to anyone, then please tell me what it is so I can fix this dang problem! If it helps, it's a 2004 EX Coupe, manual transmission, with about 115000 miles. Thanks guys!

 
Rep Power: 192

I think, most likely, your head gasket is f'd... And it doesn't matter what your oil looks like, check your coolant for exhaust gases. You can loan the device you'll need from AutoZone (I think you pay for the dye, but the tool deposit is definitely returned to you).

 
Rep Power: 286

+1 on the head gasket.

When was the last the water pump was replaced?

 
Rep Power: 812

thermostat, radiator cap, ect sensor, fan temp sensor, water pump, head gasket. could be any one of those or more. is the engine light on? does the car run fine or sometimes rough idle? make sure thermostat is oem, the aftermarket ones are junk and dont open enough. same with radiator cap oem only.

 
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lol headgaskets...

 
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is the exhaust look like white smoke, almost thick white smoke.

 
Rep Power: 368

nuff said...
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