Hi everyone.

My sister has a 95 Civic with a little overheating problem. It's temp gauge is ALWAYS about 1/4 of an inch below the horizontal mid point. But yesterday, when she was stuck in traffic, the needle went straight up towards the hot zone. I drove it around today but I couldn't duplicate the problem. I ended up coming home and leaving the engine on sitting in the driveway.

What I noticed: When the needle reached 3/4 of the way up, the rad fan would kick on and the temp would instantly go back down to normal. And it did it again. Temp would slowly climb up, fan would kick on, and temp would go down.

So i guess my question is: What would cause the rad fan to suddenly be not turning on when it should?

Thx

 

i had the same prob with my car....
i changed the thermastat and the water temp sensor that is located on the part you take off to get to the thermastat.bout 15 for the sensor and 5 for a new thermastat and prob. solved.

 

air pockets in your cooling system???

 

i would replace the thermostat and flush the system to get all the air out and then you should be good to go

 

^^^ quick question. how do you flush the system?

 

just drain the radiator plugand that will drain most of the fluid out.

 

you can use a machine that most any automotive shop has and can do the flush for you for about 70 bucks. or just drain the coolent out and leave it out, just flsh cold water through the radiator and out the bottom.

best bet for a complete flush would be take it to a shop unless you have access to the flush machine

 

Cool. Thanks guys

 

There is a flush kit that prestone made, its about $4 in your local auto parts . it comes with 3 different size T-fittings and it uses your regular garden hose for water pressure.
Youll have to splice one of your heater hose though to install the fitting in between.

 

for bleeding the cooling system there should be a bleeder valve on the housing where your upper radiator hose connects to the motor.