Two problems related to engine cooling system have been reported for the 2004 Dodge Neon.
I was driving my car one evening when it suddenly stopped accelerating. I pulled over as best as I could being on a hilly curving road in a thunderstorm. I was able to check the transmission fluid; there was no fluid on the stick. I called for a tow truck and a friend near by. We bought transmission fluid to see if that would help. We put almost 2 quarts of fluid in it and attempted to put it in gear. It didn't go into gear, just coasted backwards and saw fluid on the pavement. It was leaking from front, appeared to be hose related. When I got home and the hose from the transmission to the radiator was disconnected. The hose and connector were intact however the threads inside the radiator were stripped. I got online to see if there were any recalls or similar problems with Neons. I found out that there were similar problems with Neons from 1999-2005 with faulty factory installed radiators. Eventually the problem causes the transmission fluid and antifreeze to mix and then the transmission blows. I called the dealership where I originally bought my car, looking for possible answers. I could not believe that a car that is just under 4 years old, has just over 30k miles and I am the original owner would have such a huge problem. The dealership offered nothing. They blew it off stating when I find out what is "really" wrong with my car, then to call them. The man said he had only seen it once and doubted it was what I said it was. Forced to seek help somewhere else, I called another dealership. He had said that he had seen this problem a couple of times and knew exactly what I was explaining. I took it down and had my car back the next day. They replaced the radiator, flushed both the radiator and the transmission. It cost $760. My transmission was spared. I also contacted Dodge/Chrysler and got a polite thank for your "opinion" letter.
2004 Dodge Neon sxt. Transmission / cooling system failure resulting in antifreeze mixing with transmission fluid destroying transmission and radiator. Dodge refuses to honor their power train warranty citing the cooling system as the cause of the transmission failure, and not the powertrain. This should be a rare occurrence according to my mechanic, but it is one of the largest problems with the car online. There seems to be a major defect in these cars causing a catastrophic failure. Dealer estimated 3900 parts and labor to fix.