I have a 98 Neon DOHC 2.0L engine that overheats after about 20 to 30 minutes of perfect driving when the ac is turned on. It will drive perfect all day everyday if I don't turn on the ac.

. I have replaced the water pump and radiator with new, not rebuilt, parts. I have replaced the thermostat and bought a new radiator cap with pressure release.

I keep the system topped up with coolant.

I don't have any water in the oil or any smoke coming out of the exhaust. The car runs like a dream until it starts to overheat. I can be driving down the freeway at speed and the cars needle will start to creep up until it moves into the extreme hot zone and set the overheat alarm off. I will then turn off the ac and the temperature will gradually drop back down until it is in the normal range.

I was thinking maybe the sensor was bad, but sure enough if I stop to check the engine if it is indicating it is overheating sure enough there is stream coming out of the cap and the coolant bottle.

I never have any issue driving it until summer when I have to turn on the ac.

Any help or suggestions with what you think might be the problem will be appreciated.

 

https://dodgeforum.com/forum/1st-gen...-overtemp.html

You may be having the same problem I am. I am working on my issues now. Check the thread given above for updates.

 

i ran into the same problem here in flordia anything over 80 degrees and at highway speeds it would overheat with the ac. stop and go no problem. the problem i found was the air dam that mounts to the bottom of the core support was null and void. i gave up on finding one and made my own.

 

Make sure both fans are running at high when shes warm. What mixture of coolant/water do you use? I remember my neon hated the hot weather running the a/c. Each year I power washed the condenser and radiator to get all the bugs and crud out. Poor air flow can cause this, it did for me.

 

Hi I'm Doug I was wondering what you meant by air dam that was mounted underneath the core mount I have the same issue when I turn on my AC and it's at least over 90 degrees outside it overheats and it's only in the summer and I even have a dual core radiator I have been struggling with this since I own the vehicle for like 10 years any help would be appreciated thank you