My daughter's 1998 Neon with the DOHC engine just started doing something weird. It will run about 20 mins OK then the temp. gauge will go right to the top,stay for a few seconds then cool down again again. It cycles like this untill it's shut off. The fans both come on. Could the thermostat be only opening part way? Coolant level is good and it's nice and green.

 

it would start with the thermostat it is cheap and easy to replace

 

yes, T stat takes about 10 min if you do not break the bolt off in there like i did. then its a few hours. I give it about a 1 on a 1 to 10 scale.

 

then go with a new coolant temp sensor sinse those are pretty easy and cheap too

 

plus its right there next to the thermostat on the dohc motors

 

Thanks, guys. I kinda thought it was the t'stat and bought one today. I'll install it tomorrow. I'll get the sensor if needed. Let ya know how it goes.

 

I changed the 'stat and it kept doing it's thing. Got the sensor and installed it. OK now. Thanks again!