HELP, my car is still overheating - Honda Prelude Forum

JonathanAllyn · 08-14-2003, 10:08 PM

Well, after getting the motor back in my car after the build up(darton sleeves, Je 9:0.1 pistons, Eagle h-beam rods, etc...). I am still having an overheating issue. This evening we replaced the thermostat and bled it to make sure there were no air pockets but for some reason my fans do not turn on and its still going into the red. We pulled the cooling fan relay and he is testing it tomorrow but what are the other sensors that tell the fan's to come on?

FYI - When I turn the A/C on both fans turn on and it begins to cool the motor down but the when the a/c is off they never turn on. Now, we know the coolant is circulating around the motor because its blowing hot air, there is pressure in the hoses, the thermostat is opening and we did a pressure test to make sure the head gasket is not shot. Everything is checking out except for the fans....

Any ideas would be appreciated.

Thanks!
Jonathan Allyn
http://www.jonathanallyn.com

JonathanAllyn · 08-14-2003, 10:10 PM

BTW - this is a 1994 H22a1 with a new water pump.

cantdrive55 · 08-14-2003, 10:11 PM

Coolant temp sensor, I believe it is located around the thermostat...

jtcdudeman · 08-15-2003, 10:05 AM

good to hear you got it built up... I liked it in Alabama alright.. Now it sounds liek either your coolant temperature sensor is gone or you still havent fully bled your coolant system.... Mine took over an hour to get right... i also attached a hose tothe bleeder screw and let it run straight up to a bucket.. Once it wass pressurised enough the colant will flow out and up to the bucket w/o any air in it... But the way you describe it your car isnt getting that warm.. just ur sensor is.... Now, is it at a shop? Because they shuold be able to use a temperature sensor to determine if oyur runnig hot or not..

[SUB[EX] · 08-15-2003, 01:16 PM

Replacing you radiator couldnt hurt. It would a shame if you destroyed it after all that $$.

JonathanAllyn · 08-15-2003, 01:49 PM

Yeah, I have thought about replacing the radiator but coolant is running through it so I am going to try everything else first. We beld the system for over an hour last night but i think i am going to try the bucket & hose idea as well.

We think we may have isolated it to the one of the sensors because my fans do not come on at all unless I turn on the a/c. I went by the motor company today and picked up the two temp. sensors that screw into the head. One of them goes on the goose neck on the front of the head and the other goes into the thermostat housing (i think). I know my temp guage is working correctly because we tested it so I hope one of these two sensors that I replace tonite kicks my fans on.

Does anyone know which one is responsible for turning on the fans? Is it the one by the thermostat or on the front of the head?

Thanks for your input!
Jonathan

jtcdudeman · 08-16-2003, 02:00 AM

its the one on the front of the engine.. the one where the coolant comes out and goes back up to the radiator.. its by far the easiets to get to and locate..

JonathanAllyn · 08-17-2003, 12:11 AM

We figured it out. Easy, easy easy,....

My car did not have enough grounds and it turned out that my thermostat sensor was grounded to the motor instead of the thermostat housing. Once we put a few more grounds in everything came to life and its running very good!! This week comes the turbo, hondata and all the good stuff. I have pictures and will post them when everything is done... ; )

Take care... ; )
Jonathan Allyn

irishpilot · 08-17-2003, 01:22 PM

good to hear