For some strange reason my cooling fan only used to come on when my car was off. So, I manually turned on the fan. But for some reason, if I am in traffic for an extended period of time, my car still over heats. Fan is on, coolant is full, no leaks. What can be the problem causing the overheating? 94 accord in my sig.

 

stuck thermostat

my 92 accord fan used to come on immediately after i turned my engine off. engine temp sensor 3/4 way up to HOT. my coolant would evaporate or something because it kept getting low. Changed thermostat, coolant levels constant, fan doesnt turn on no more after immediate car shut off. engine temp levels in center.. temp not real not this time of year either.

not referring to AC fan, it works fine when AC is on.

 

ok, i will love to find out that's the prob. (I have 3 new ones laying around), where is it located?

 

thermostat: its on the left side of motor near the rear side of the engine where the huge coolant hose (lower coolant hose) goes into the motor, behind dizzy. drain coolant and there should only be 2 screws and the housing falls out and the thermostat sits in the pocket. check out cb7tuner.com for more accurate info.

also if that doesnt do the trick you can check the thermostat fan switch, located on the thermostat housing itself, it could go bad.

refer to this thread
http://www.cb7tuner.com/vbb/showthre...ght=thermostat

 

there are only 5 things that will cause a car to overheat

1. bad thermostat
2. blockage in system
3. your headgasket is shot
4. leak or crack (block) in the system
5. waterpump failure (impeller worn down or shaft busted)


most common reason is thermostat faulure and that is a $15 fix (temp guage is above 3/4 or hot and car feels weak)

next most common is a leak (green stuff on the ground)

It is rare for a radiator to become clogged unless you used some sort of stop leak or you have never replaced any of the coolant

water pump failure is rare

it is not common for hondas to pop head gaskets unless the car has been severely overheated

if you got coolant in your oil you might as well go straight to rebuild since you gonna tear the engine apart to get the HG replaced

 

I will check the thermostat, then the fan fan switch since the fan refuses to turn on automatically. My car does't leak any coolant. I hope its the thermostat. thanks

 

Keep an eye on your coolant level for a few days before you start it up each day to see if the level is going down or actually that you are still bleeding air out. Sometimes air pockets get trapped and work themselves out naturally, sometimes they dont.

This is after changing the thermostat, of course.

 

Ok... i check out my car....

1)the engine had no thermostat in it, so i installed one which is suppose to open or close at a lower temperature

2) the is not coolant leak

3)not coolant in oil

4)fan is hooked up on a manual switch

but it looks like my car still overheats, just not as fast

what does that sound like is wrong?

 

Air in the system was not mentioned and just because there is not coolant in the oil does not mean that the head gasket is good, the coolant could be going into the cylinders, or worse yet, no coolant is going into the cylinder but hot exhaust is going into the coolant.

There should be a chemical test kit at most parts stores to test the coolant for HC or CO to see if there are signs of a head gasket leak.

If the cooling system hoses are getting hard quickly then you may have a blown head gasket, if you let the system pressurize and then remove the cap safely so you dont get burned, put the cap back on and the system repressurizes, then you do have a blown head gasket.

The system should only pressurize one time as the coolant expands from getting hot, once that pressure is released, it should not pressurize again until the next cool down and reheat cycle.

 

I will try to take off the cap once it is hot in the morining... what is considered getting pressurized quickly(how long)? Do you mean getting pressurized quickly in gerneral or upon startup from cold?

 

Pressurizing from cold, well I would not put a stop watch on it, I probably would not even test that, I would only release pressure safely after the cooling fan had come on two times and then see if it pressurized at all after that, then I would lean towards a bad head gasket.

 

NEVER EVER EVER OPEN A HOT COOLING SYSTM = UR *** GETS BURNED

car is on level ground and COLD

next open rad cap and fill with coolant mix

next fill overflow tank to max mark after you empty and rinse it (if there is crud in it)

start the car and add coolant to the rad as needed

when the rad is full put the cap on

should be a nipple on top of the t-stat housing open it up

watch the nipple on the t-stat housing and wait for all the bubbles to dissapear, close nipple

drive car to get it nice and hot

park car

after car has cooled down for a about 4 hours check over flow tank and add coolant as needed. continue to check for next few days and add as needed

what Duane In Japan means is once the car is warmed up the system will be pressureized and the top hose will be HOT and HARD if it isn't u most likely got a bad water pump or rad cap (in this case the coolant would be bubbling out of the overflow tank) assuming the system is not leaking. if the hose is hot and hard and it still bubbles out of the overflow tank, replace the rad cap.

 

coolant is not watered down is it? just wondering.

 

no, i recently emptied the radiator, and put in new coolant. But i was watered down for a will b4 that.


I will try this tomorrow

 

the top how pressurized. when i took of the radiator cap it soften up, but didn't re-pressurize immediately once i put it back on

 

so if it goes down, add coolant? correct?

 

if you follow what I posted, you should be good.

if you open the cap the system will loose pressure and the top hose will get soft. once you replcae the cap and the car is running, it will repressureize after a short while

 

It will take it's good time repressurizing considering the coolant is already hot. Once it cools off from driving and then reheats, the pressure will return.

P

 

what are common head gasket failure symptoms?

My oil looks like oil, and no coolant is coming out the overflow bottle

but after driving it long traffic my oil light starts to blink even though the oil is full

thanks