Jamie Steadman

Right, so, friend owns a Honda Civic 1999, v reg. Everything is working fine until last week when the temp gauge starts getting a little high and the fan wont kick in.

I check the fuses and relays, everything is fine. Unplug the fan switch and close the circuit using part of a paper clip and fan works. So I know that there isn't a problem with the fan itself. I take a little look online and it appears that it's the fan switch. Off we go to get a new one and also some antifreeze (might as well change the coolant too).

I swap the switch over, drain all of the coolant and add the new lot. look for a bleed hole, which there isn't (not sure why, maybe someone does?) Anyway, so I do what I have read and bleed the system while running it with the radiator cap off let the bubbles come it (squeeze the hoses to burp the system) all while the heater is set to hot. The bubbles stop and temp is showing normal at idle, i close the bonnet and after a few minutes, the temp goes up a little and the fans kick in. Everything seems good, then while taking it for a test drive, the temp needle seems to rise but while I'm going down a main road at 40/50 mph. after about 3/4 minutes the needle is almost at the top, I turn the heater on and it drops back down. I stop and open the bonnet to find that the reserve tank is full where the radiator has pushed coolant into it. Why is this happening? The fan doesn't seem to kick in while driving the car, is it the thermostat? Or the head?

Any help is appreciated.

Thanks for reading.

NotARaCist

iTrader: (1)

You may have overheated it to the point of damage. It's extremely easy on these cars. Go to your local parts store and buy/borrow/rent a block testing kit, and use it. It's extremely self-explanatory. When was the thermostat last replaced? Was it replaced with a proper OEM unit, or a parts store unit?