Alright so I have been having some overheating probs this summer, or at least my car thinks it has lol. Here is the deal, driving on back roads at speeds of 60 and under the car can run all day just fine with the temp gauge in the middle. Also when idling (usually when most overheating cars have probs because of the lack of air flow) the temp remains fine. However on the highway going at 80mph running at 3.5 - 4 thousand rpm's in 5th gear the temp gauge will rise and rise to the point of it overheating, which is odd because that is when the most air is going under the hood. When this happens I turn my hot air on the lowest fan setting and the temp will instantly go down back to the middle within 10 seconds. This is leading me to beleive the car is not actually overheating. How could the water temp drop that fast from red zone H to the mid by the water temp symbol, especialy on the low fan setting. I had my collant system pressure checked for leaks and there were none, my fans come on just fine and my coolant level stays constant. Any suggestions as to my problem? Idles fine, drives fine on backroads, its only the highway at speeds around 75-80 mph that my temp gauge will rise.

 

I just went on a 120mile trip tothe OshkoshAir Show to see the B2 Stealth Bomber fly over at 3pmthis last Saturday and I drove 75-80 the whole way with my temp gauge about a quarter of an inch from being maxed out, I was running 3400Rpms. Of course my car eats anti freeze like 5 year olds eat candy and it could have just been low. I've found out that filling the cooling system with antifreeze Via the overflow container at rear of engine is a waste of time and doesnt provide an instant result when engine over heating is ocurring!- I notice my car will run cool instantly when I pour the Antifreeze directly into the Thermostat housing, only problem is I'm chickn **** when the engine has been running hot and I tend to wait till the car cools down so whenI open the cap anti freeze doesnt spray at me.

My car did the same thing on the highway, would overheat going 75-80mph but run a bitunder the middle going 65mph hmmmthe thing is its only 500rpms difference or less from 65mph to 80mph in 3rd gear on my automatic so I don't know if thats Mopars way of telling us lead foot peeps to slow down?. I carry a jug of antifreeze with me where ever I go in my trunk and when its capped off with antifreeze I don't notice it overheating.

I take it my 98 Neon has the factoryhead gasket upgrade, I was less than a quarter of an inch from maxing temp gauge out for 25miles on the highway and she didnt blow,especially when I raced a riced outSuburu for my off ramp position and waxed him going 115mph lol, after that I remembered my car was in jeopardy of overheating and almost beat myself with the thought of blowing my motor, but luckily it didnt blow and it still runs like a champ!.

After all that beating of my Neon I missed the B2 Stealth flyover [:@]if I was riding soloI might have went 100 the whole way or at least more than 1 once

 

So based on the other thermostat post floating around I was thinking of replacing it to see if this fixes my problem. My car didnt do this last fall and since I have put it back on the road for summer this has been a new development. It just seems weird that the temp could drop instantly so much upon turning on the heat, and that it only does it on the highway, not anywhere else.

 

Probably wont help, I changed my thermostat a month ago and I'm still overheating [:@]Only cuz I have a leak somehwere and it loses coolent and I have to cap it off every month.

 

See mine is not loosing cooland as I had the whole system pressure tested. It just starts overheating when I am driving on the highway and only the hgihway. I have no clue as to what could be wrong.

 

check to see if its losing coolent, yeah mine doesnt loose coolent it loses it.

 

Yeah my car does the same exact thing! overheats (93% hot on gauge) once I hit 75mphbut runs very cool at 65mph (about 35% hot on the gauge at 65mph) 10mph difference isnt much for it to be overheating like that. WTF!

 

Replace the radiator if a new stat doesnt fix it.
or try flushing the cooling system good and run som cleaner through it first.
stock neon radiators are junk and they only last a few years before they start falling apart or clogging up.
my 96 had 85k miles on it and the radiator was junk in it.