just put it my rebuilt b18, and i have a overheating problem

the radiator fan is not coming on, the car starts to overheat and goes past the half way mark and rising (never used to go over half way before)

bottom radiator hose is cool, so i thought the thermostat was faulty, so i removed the thermostat and tried it without and it does the same thing and bottom rad hose is still cold...

when you turn the engine off and release the pressure from the radiator cap, the fan turns on... i thought maybe theres air in the system, tried running it up with radiator cap off to see if theres air in the system but no difference..

any idea's?

dan

 

Honestly if the fan isn't coming on I'd check the relays and the wiring to the fan for starters. But if your radiator hose isn't getting hot even with the thermostat taken out, then your water pump isn't working.....

I'd check the water pump first thing before you blow the motor.

 

hi mate,

theres nothing wrong with the fan or switch, the reason the fan isnt coming on is the bottom rad hose/thermostat housing it staying cold so the sensor doesnt know its getting hot..

all i can think is theres alot of air in the system???

as the bottom rad hose is cold even without a thermostat in it..

 

WATER PUMP....if the bottom hose is staying cold even without a therm in the system, the the water isn't circulating, meaning your water pump is probably blown, or you don't have the belt ran correctly somehow when you rebuilt the motor. I'd take the water pump out and replace.

 

Water pumps don't really tend to fail especially with how honda has designed theirs.. I had a similar problem and it turned out to be my cylinder sleeves cracked in 2&3 if there is alot pressure being released after the car has cooled down from the radiator cap then you have exhaust gasses leaking into the cooling system. compression test your car

 

put a new thermostat. should work.