my 97 neon is overheating. I’ve replaced the Rad. cap twice, Flushed the system,replaced the thermastat, run without the thermastat, replaced the water pump, It will go about 20 minutes and then start to get hot?, I don’t see water in the exhaust, In was about to replace the head gasket, when i happen to have the overflow hose off and saw water rapidly coming out of side of the fitting by the radiator cap. could this be the problem or just because the hose was off, I’ve change the cap twice already?? I live in the deep south with a lot of humidity, there dosen’t seem to be an excessive amount of vapor out of the exhaust, any help would be appreciated.
You could be getting bad radiator caps.
I had the expierience of getting bad radiator caps to the point where I brought my Stant cooling system/radiator cap tester to the parts store with me. After there were a half dozen radiator caps sitting on the parts counter, I finally found one that held the proper pressure.
Tester
It could well be bad caps, but your engine is overheating and when it does the cap is supposed to relive the excess pressure, so it is hard to tell if that cap is the culprit unless you test it.
If your timing is off, that can cause overheating. If there is clogging in the radiator flushing will not always clear it, and it may need to be removed for a core-out.
The head gasket is not off the hook, but do a pressure test first, particulary looking for low pressure on adjacent cylinders. I assume you do not have coolant in the oil, but that is only a symptom of one kind of head gasket failure.