Can anyone tell me why my sons 98 Neon overheats?It will set at idle for as long as you want and won't go above normal on the temp gauge,but if you take it out and run it at 55-60 it will overheat within a couple of miles.If you run it around town and some of the time it stays normal and sometimes it overheats.I put in a new thermostat and the problem remains.Does anyone know why?

 

check the oil and make sure that there isnt any coolant in there, then the same with the coolant...it could be a problem with the head gasket...if this is not the case then the waterpump could be going bad

 

Yeah spuds right. if you find nothing in those tests try more bad headgasket tests. gurgling anifreeze tank, antifreeze in oil( looks milky) oil in antifreeze, turn heat on and see if the heat goes from warm to cold to warm to cold again, antifreeze smell from engine and tail pipe, and white smoke, I had my headgasket changed about a month and a half ago and I had the gurgle,white smoke, and anifreeze smell as symptoms so the previous info comes from experience, and as for the water pump check under the car to see if you have any antifreeze leaking, when my water pump went bad you could tell, I would put water in there and when I parked the car, the water would just pour. really hope its not your headgasket because thats gona cost you some money if you dont do it yourself and even in that case you would need to have your head milled and valves polished for better protection and to make sure the gasket seals good Good luck and I hope some of that was helpful

 

this will sound strange but i overlooked this one and beat my head against the wall for a bit till i noticed the back side of the radiator ( motor side ) all the coils were falling out

 

Antifreeze and oil look fine and water pump is'nt leaking,radiator looks ok and the fans are working.Is it possible the water pump is not work properly at higher speeds.If he drives around town or just lets it idle it's fine,it just overheats at highway speeds.

 

well thats good, I was really hoping it wasn't the gasket the only thing I can think of besides the water pump is maybe blockage in the radiotor, or maybe the radiotor cap isn't holding pressure like it should. but as for the water pump its possible it could be going out

 

Most overheating is from leaks. It doesn't take much... Took me several weeks to find my last one, tiny pinhole where the top end bell joins the core on the radiator. So small that any coolant would evaporate immediately. Finally took the rad out, plugged it, and stuck it in the bathtub (much to my wife's dismay), and saw a little trickle of bubbles...

Just that tiny leak would cause the car to overheat randomly. Most of my time was freeway driving, about 150 miles a day. Sometimes it would overheat within an hour, sometimes it would go all day without alarming.

Also keep in mind that the recommended replacement interval for the water pump is 105,000 miles, same as the timing belt. If you're son's car is over 90k miles, it's probably a good idea to get that done...

But the other suggestions are good as well. If it isn't something obvious like the fans or a stuck thermostat, it's tough track down sometimes... A car under load generates more heat, obviously. Blockage would reduce cooling efficiency, so there would be a larger spike above the fan setpoint. Fans come on at 220F or so, the dinger comes on before 225F. Not much wiggle room.

Best of luck!

 

yah i have the exact same year and the same thing happened to me last year, check if the fan cuts in when its starting to heat up, if it doenst its the temperature sensor for the fan, i got a new one, fixed the problem.

 

I think we will go with the water pump.The fans are working ok,when he got it they were hooked up so they come on when you turn the car on.As for a small leak we have never had to ad any coolant,that and the thermostat were the first things I checked hoping it was one of them.