justrx8

1984 gsl 12a overheats in about 10 min. i have removed the t-stat and install an ele. fan but still overheats anythins else before i buy a new radiator

DriveFast7

iTrader: (1)

did you replace the thermostat or just remove it?

if you removed it, there is a problem. the water pump HOUSING has a 1/2" bypass hole in it. thermostat routes coolant into that bypass hole and back into the motor, bypassing the radiator, when temps are cold.

you should put a brand new MAZDA factory thermostat in there; i don't like aftermarket ones, they have their own issues....

have you done a PRESTONE coolant system flush yet? Get all the brown outta the radiator and motor before condemming the radiator!!!!

fresh distilled water and prestone coolant 50/50 ratio??

water pump belt tight and spinning properly?

coolant leak?

radiator cap tight and sealing?

you get the idea. check everything!

justrx8

ok here what i have done so far new rad. cap ,removed the t-stat and a new ele. fan thats runs all the time. i will install a new (mazda) t-stat on monday at my shop were i work. i pressure test cooling system last week it
holds pressure fine. thanks for help Pedro

KYPREO

you CANNOT run with no thermostat unless the bypass is blocked. It is also desirable to place a restrictor where the thermostat sits if you choose to delete it (suggest thermostat outer ring supported by gaskets).

what size/power electric fan are you using?
PS...electric fans are not designed to be run all the time - defeats the purpose IMO. If the radiator is healthy, the fans should only need to come on when there is insufficient ram flow (ie below around 10-15mph). The fan should be thermatically switched at around 90 degrees. My fans come on when the car is stationary, a/c is on, or hauling uphilll - thats about it.

rhinor61

Make sure the electric fan is big enough to pull air in, plus you should probably look for a new radiator to replace your 20 year old one.

If anybody ever ran radiator stop leak in it, you are doomed to try to cool it down.

Remember on the '84 non se they use water to cool down the oil.

John

justrx8

so were do i get a thermatic switch from . an how do we hook up , do I have to in a sensor for the for the cooling fan so they come on and off like on the newer cars also how i block off the bypass or do i need it at all for heat inside the car

KYPREO

You need some kind of sensor - either a capillery tube connected to an adjustable temp switch - there are generic electric kits around. Mine is made by Davies Craig, an Australian company, which I don't would be readily available for you.

The other choice is use an OEM temp switch in the position of the factory temp switch in the thermostat housing. The factory switch operates below 80 degrees (C) to switch the choke off, but you could go to your local dealer with the thread width and ask for a 90 degree (C) switch - there are a couple of late-model car thermal switches which fit. Can't remember which - I believe they are Fords.