hi guy's

have a mazda626 95 that i just changed the thermostat in thats was over heating.it idles fine without overheating but when you start to drive it the temp flies up. but oly when you drive it.had dealer change water pump @110,000 the original was still good when i had the new one put in.it's got 160,000 now but even the dealer says the water pump on a mazda shouldn't go out that soon.not factory anyway.not to say it couldn't be but its rare.the fan comes on like normal when it gets over 1/2 way but quickly cools it back down.any help please!


clow

 

It sounds like the beginning of a head gasket failure. It is possible to have combustion escaping into the cooling system. There is a simple test that can be done to rule this out. There is a kit available that tests the coolant vapors from the radiator when running. It has a dye that will change colors depending whether or not there is a problem.

Another thought is a collapsing radiator hose not allowing coolant flow. I have seen this on other cars when revving up the engine. Are the radiator hoses in good condition?

 

I have a 93 626 and the water pump is not working and I can not get it to over heat. at least I dont think the water pump is working because one of the rad hoses well collaps after the engine has been running a while

 

The water pump is driven by the belts on front of the engine. If your water pump was not working your engine would overheat in a matter of minutes due to no water circulation.