I have an 2003 Dodge Neon. I have replaced the thermostat, radiator cap, and flushed out the radiator. It's fine when I just drive it around town, but if i go a long distance it overheats. I can turn on my heater and the temperature gauge drops back down. It really only does it on really hot days. How do I fix this?
Answers from the Automotive Experts
If you have not replaced your upper and lower radiator hoses, I recommend you do so. After replacing all the components that you have, with still having overheating issues you may have a weak hose internally. Do not rule out your temperature sensor sending unit.
It could be an air pocket in the cooling system or a fan that's not working properly. First take cap off when the car is cold then start car and let it run to release any air. The Dan will turn on when it gets to about 200 degrees. Just make sure car is cold before taking radiator cap off. After air pockets are released add coolant to fill system completely
You may have still have a fault in the cooling system, either the water pump is not putting out enough or there is another restriction in the cooling system. The radiator may still be clogged.
It is also possible that the cooling fan is not operating as well as it should be.
Your best bet would be to take it to a qualified repair shop and have it properly diagnosed.