my car has a flustuating temp. its very bad, i can drive around for awhile and the temp will just start rising almost to the h then drop down after a couple of sec. but if i fill up the radiator completely and the overflow, the temp won't fluctuate. and it only lasts for 1 drive then when i stop the overflow starts pourin out. any suggestions?

 

umm well your rad should be full... and there shouldn't be a need to fill it each time.





my guess is your water seals are gone. hitting the H once will pretty much kill this. if this is the problem. a new engine or engine rebuild is the only way to fix it.



I would start off by changing the thermo stat (mazda one only) and rad cap first. as that is alot cheaper.



and also. with the car cold. undo the rad cap. and start the car. and have somebody watching. if water sprays up from the cap. the seals are gone.

 

check your fan clutch. to do this start your car and let it idle then see if you can stop the fan w\ your hand or a screwdriver if you are scared