in the past 2 months i have replaced the water pump the thermostat and the radiator cap. i recently found out it was a cracked head gasket. i got that fixed but it still starts to overheat unless i keep the heater running. the check engine light flashes but nothing comes up on the computer. i dont know what else to do if anyone could help that would be great! -brad

 

did you have head checked when it was off for hairline fractures and did you have it "planned" for warpage, or just lift and swap the head gasket???

 

If the gasket leaks at all it need a shave, called resurfacing, which requires removal of the valves. This happened on my '98 and I have to replace the cooland temperature sensor on the exhaust manifold just to the passenger side of the fuel rail, ir began to short for some reason. $15 fix. I also ended up having to run Prestone Super Radiator Cleaner, which was an epic fix, my coolant system is perfectly clean now. The temperature doesn't even wiggle anymore after warming. Tthe Prestone is a $7 product, and cleaned out the fins on my radiator, which were getting clogged. Try those fixes before you unload tons of money at it. I reccomend this assuming your fans are working and you are not dealing with a full-on overheat problem. The heater controlling the temperature suggests that no one part of the coolant system is failing completely.

 

*sigh* working from my phone I cannot edit my post but I just realized I should not type after 2 days no sleep. I suggested that you replace the "coolant temperature sensor" and it is obviously on the intake manifold, not the exhaust *facepalm* the sensor was tripping the check engine light but not giving a code.

 

my 99 dodge neon is the sport model the DOHC and i had the cracked head gasket fixed using Steel Seel if you have ever heard of it. so i didnt see what the head gasket looked like but i knew air was getting into the system. the overflow use to bubble up but it doesnt do that anymore so im assuming it worked. so your saying its possible to need to replace the coolant temperature sensor even if it isnt giving the code? because i am thinking about doing that.

 

Check ur fan relay switch its under your battery box