Cooling system problem, Advice Please

[MuzzleFlash40]

My friend has a 1998 Plymouth breeze with the 2.0L.

He said it was overheating and loosing coolant but didn't know from where. I checked it and the overflow tank was full but the radiator was very low. I added straight water since whatever was causing the problem was going to cause me to have to empty the system anyway. After adding over a gallon of water to it we took it for a drive. The temp guage didn't move past the middle of the normal range. A/C worked fine. After stopping and letting it idle I could see dripping underneath it. Coming from the opposite side from where the hoses are. So I'm guessing the radiator is leaking. After it sat idling for about 15 minutes you could hear boiling under the hood. And was coming out of the overflow tank. But the temp guage didn't move to say it was overheating. It was 60 degrees here today if that matters.

Could the pump be bad? Bad temp sensor? Or was it just having water alone enough to make it boil. I'm not sure where to go here.

 

[spasm3]

If it has coolant mixed with the water it should not boil over, with a normal temp gauge. It might if its just water in there. A bad head gasket could pressurize the system and push coolant out.

 

[Kuato]

Sounds like it is overheating, a small leak wouldn't cause that in 15 minutes. Has it been OK all winter, then started this once it warmed up?

Several vehicles I've helped with had a gradual clogging up of the radiator that caused it to overheat when it was hot out, but to be fine in the winter.

Other thoughts:

Thermostat stuck closed, or pump is bad. In that situation I'd let it cool, then remove the radiator cap. Start it up and watch to see if the coolant is moving in and through the radiator, and if it changes from cold to warm to hot.

 

[JHZR2]

Those cars did have HG issues, was a replacement ever installed?

 

[doitmyself]

I've had similar symptoms when the water pump went bad. See if you can locate the water pump and see if the leaking is originating there.

EDIT: a quick search indicates that the water pump is buried under the timing belt cover?, so I am not sure a visual inspection is possible.

 

[JamesBond]

If its a non-pressurized reservoir, the little hose from the top of the radiator to the reservoir can get clogged or become loose. This will cause a loss of coolant from the radiator even though the reservoir is full. Enough loss causes overheating to the engine but the reservoir remains full.

Pull the hose and make sure its clear, then secure it with some small hose clamps or zip ties.

 

[IndyIan]

When the HG went on my Neon, it would make a boiling/bubbling sound after I shut it off. It could be just the system loosing pressure though, squeeze a hose to see. With no pressure then you can get localized boiling even with the correct coolant, but with mostly water in it, it would boil more easily.

 

[MuzzleFlash40]

Thanks fellas. I'm going to do a pressure test on it this weekend, and do a few other things you guys have mentioned and check back in. Hopefully I'll find some answers and see what you guys think.

 

[Kuato]

What did you find?