i dont know if this is overheating but when i drive my 91 accord, the temp needle is at normal...but once i get to a red light, or stay idle for at least a minute, the needle just rises to the "H" level...but the minute i take off, it just flows back to normal.....i checked when i got home and the cooling fan doesnt turn on until it gets to the "H"....is this normal?? i dont think it did this before, this started happening for a week now...i checked my antifreeze level is its pass max...anyone knows wat it could be? i dont want to overheat the car in any way

 

My best guess would be that you need a new thermostat. Anyone else?

 

yeah sounds like the thermostat has gone bye bye. Has the timing belt/water pump been replaced yet? your water pump could also by dying, or your radiator/cooling system could have a small clog somewhere.

 

This could be a number of things.

I would first check the coolant level in the radiator to see if it is full (ie no leaks in the system).

Turn on the A/C and make sure that both fans turn on. The air moving through your radiator when driving may compensate for a fan that isn't operating.

I would think that a bad thermostat would give you overheating problems all the time, but it is a relatively cheap part to replace.

The fins in your water pump may be worn enough to cause this problem. That would be the last place I would check, because that is an expensive job due to having to basically change the timing belt.

 

At 91k you are due for a tbelt change anyway (unless it has already been done), soif you decide toget it done, do the water pump too.
I was kind of thinking if it was the thermostat the car would be overheating all the time, but could the thermostat be "partially" malfunctioning?
I would start withdiagnosing the fans, then the thermostat, then the h20 pump. Iguess I am kind of being "Captain Obvious" here.

 

Yes, you might as well get any air out while you're checking the levels. Start with a completely cooled down car. Remove the radiator cap and fill the radiator with 50/50 coolant until full, start the engine, turn the heater all the way up and the vents on high. As the car warms up bubbles will start to come out (assuming there is air in the system) of the radiator cap and the fluid will slowly go down. Keep adding coolant until the level stays the same.

Be careful, we wouldn't want you to get scalded, I put a towel over the cap as I remove it just in case.

 

My bet is a bad fan switch. It's the 2-wire'sensor' in the thermostat housing.

 

did anyone say radiator cap yet?

 

anytime the temp gauge needle goes past 1/2-5/8 engine is overheating,

are BOTH fans coming on?? put the a/c on and see if BOTH fans come on they should .......
also feel the bottom hose of the rdiator and see if it feels as hot as the top hose if it does t-stat is opening up ok,, if it feels warm or cool,, t-stat is stuck or partially stuck closed
also it is a good idea as well to chk the radiator cap.
assuming you do not have any coolant leak and low on coolant of course
let us know .. butthe the fans operation