My 95 civic DX was overheating a month ago. The temp was all the way to the red. After I researched, i realized the radiator fan was not running. So, I checked the fan, the t-stat, the cooland switch sensor, etc. After I changed the t-stat and coolant switch sensor, the fan works.

Last Friday, the car overheated again! The temp was all the way up at the red zone. The radiator fan is not running again! So, I checked the fan and the t-stat again. Both of them are still good. Is it possible that the coolant switch sensor is bad again??? How do I check the sensor to see if it is bad? Could it be headgasket leak?? Could it be water pump not working? How do I check??

I am going to throw this out there too. When I refill the coolant, i noticed that the coolant is muddy with some white residue. The white residue looks like the oil on your overnight leftover meal. So, I drained the coolant and refilled it.

I still can't figure out the problem. The fan is still not running. The car runs like crap. It is shaking when on idle. HELP!!!!!

 

sounds like a blown head gasket to me. that tends to cause a mud to form, but it's usually a darker color...
anybody else?

 

yeah i think so to. cant figure out what the white stuff is tho

 

I'm thinking the color *may* just have something to do with the type of coolant.

 

Is there any coolant in the oil? Remove the oil cap and look under it, is it white?
Any excessive presure building up in the coolant system from gases entering it?
Where is the coolant going? Is it overflowing from the expansion tank or anywhere else? If not, you may be burning it. How's the exhaust smell/look?

The water pump may be bad, if you see coolant leaking out the weep hole of the pump, then it's bad.

You could have a bad t-stat (even though it's new) or rad cap. It could just be air trapped in there, did you bleed the system?

You may have to have compression test and/or leak down test done to find out if the head gasket is bad.

How long does it take to start over heating? My aux fan rarely runs-especially this time of year.

 

Right now, the car is not overheating. But I have not driven it for long distance. Drove for 10-20min then stop. Then drove 10-20min then stop. The radiator fan is still not running. I noticed the coolant was still overflowing from the expansion tank. The upper coolant pipe was hot, and the lowe coolant pipe was not as hot, but warm.

Any idea what could be wrong??

 

There's the bleed screw on the left front of the motor (just loosen it carefully if it has never been or it could snap off).
White smoke isn't really a good indicator if it's cold out, but if it's heavy white smoke then MAYBE the head gasket.

In these short trips, is it still using (loosing) coolant?

Without the the compression and/or leakdown and/or coolant sniffer test, it's hard to tell, especially with the short trips.

There's gotta be a way to test the fan for proper operation, I just know how. I'll see if it's in the Haynes manual.

How old is your radiator cap?

 

head gasket.

I had the same problem. The car will run fine driving around for a short period of time and not overheating is deceiving.

Drain your oil. It should look like a mocha latte.

 

Yes.. it was heavy white smoke coming out of exhaust. And, the exhaust was sputtering too....

I still can't figure how come the fan is not turning on. If it was the head gasket, would it affect the cooling fan??

The radiotor cap is as old as the car.

 

Dude... You have a blown head gasket!!!!!!!! The white smoke means that water is getting in to your combustion chamber. When mine was blown, my fan didn't turn on either. I don't know why, but it didn't.