Hi I have a 2000 Dodge Neon with a 2001 Neon motor in it. I have just recently had problems with the car overheating. So we started diagnosing it and replaced parts that we thought were wrong. We replaced the water pump, thermostat, radiator cap, and timing belt. The problem that I am having is that the car won’t take coolant out of the reservoir tank. I have bled the air out of the cooling system and it still didn’t fix the problem. I really don’t have any clue as to what could be wrong anymore.
Do the radiator fans turn on?
Yea i had to wire a switch to it because there was a problem with the relay connection.
As the coolant in the radiator cools off when the car is stopped, its volume decreases and thus a partial vacuum is created. This vacuum pulls the coolant out of the reservoir tank. If the coolant is not being sucked back into the radiator, then there is a leak that is causing the loss of vacuum. There may be a leak in the top of the radiator. Another possibility, although rare, is the hose between the reservoir tank and the radiator is collapsing when the radiator tries to draw back the coolant. This is rare, but I had it happen on a 1993 Oldsmobile 88 that I once owned. A couple of dollars for a new hose and clamps and 10 minutes of my work took care of the problem.
I’ve seen a radiator hose do what Triedaq has decribed, collapse in on itself and prevent coolant from being drawn back in through the radiator cap. The cap should be the easiest “valve”, but life ain;t always that way.
Is one of your hoses collapsed in on itself when the engine is cool?
No the hose that is running from the reservoir tank to the radiator cap is still in form and not collapsed in on its self
I don’t like the sounds of this. You might have a head gasket leak sorry to say. That would force air into the coolant system. Have a block check done to see if exhaust gases are getting into the coolant. If you hear air bubbles getting into the coolant reservoir when you shut the engine off then that would be a bad sign.
damn ok. another thing it does is when i open up the radiator cap a lot of pressure is released through the reservoir hose into the reservoir tank.
Neons are very prone to head gasket problems, so yours may have the same thing. You need a pressure test done on the cooling system to identify any leak. The head gasket runs about $900 if no other damage is found.
The problem with drawing the coolant back into the radiator is most likely in the overflow tank itself. Overflow tanks will have either a tube hanging down from the cap into the tank or a molded tube in the side of the tank itself. Either way, it is like using a straw for your soda, if the straw isn’t immersed into the liquid, then you only suck air. If the straw has a crack or hole in it above the liquid level, then again, you only suck air.