1999 Dodge Neon overheat every 40-50 miles of driving

Hi all, like I mentioned in the title I have a 1999 Dodge Neon with approximately 107,000 miles in mileage (I don’t know the engine size). The problem I am having started about a month ago, the engine overheat after a long drive. I noticed last week that it overheats every 40-50 miles then I have to stop, turn off my car, wait a few mins, open the radiator cap, and pour some water into it then drive for another 40-50 miles then I had to make another stop.

So far 3 people have checked the car: 2 of my friends and one auto shop, none of them found out what the problem is. Part of the problem is the car didn’t overheat everytime they checked it. All of them said that the radiator is fine, which I don’t know how they tell that the radiator is working fine.

The last thing that I did before the issue came up was oil change (a month before I got the problem).

Some other stuff that I noticed:

1. The water/liquid in the overflow tank acted like boiled water when the temperature gauge gave me a warning, so I don’t think it’s a faulty gauge.

2. My instrument panel actually has been acting strange in the past couple months: the needle on the tachometer will sit on 8 (all the way to the right) instead of 0, sometimes the speedometer doesn’t work esp. on rainy day or I drive around on bumpy/rough road.

3. Last week during the trip I made 2 stops to cool down the engine and filled up the gas tank. But the gas pump acted like if my tank is full which is not true since I’ve drove 60 and 40 miles before I filled up the tank. The fuel gauge also say the tank wasn’t full, so I’m not sure if there is a connection between this and the overheating issue.

Thanks in advance

Sounds like a blown head gasket. To check, install a cooling system pressure tester on the radiator. Don’t pump it up. Start the engine and goose the throttle several times while you watch the pressure gauge. If it jumps a little every time you rev the engine, the head gasket is blown.

In your case, after 50 miles or so, this extra pressure blows enough coolant out to cause the overheating…

Caddyman is right. The head gasket is almost certainly blown. Coolant is getting into the cylinders, and being consumed and blown out the exhaust. When it gets REALLY bad you will be able to see white steam coming out the exhaust all the time.

In addition to the test that Caddyman mentioned there is another that involves drawing a sample of the gases in the radiator through a reagent liquid with a special tool. If the blue reagent turns gold, it is showing the presence of exhaust gases in the coolant. A blown head gasket is the usual cause for their presence, although a cracked cylinder head or block will cause it too. .

Both tools are available on Autozone’s tool rental program, but you have to buy the blue liquid reagent to use the latter. You’ll get enough for about eight tests in one bottle.