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What does it mean when the overflow tank is bubbling yet the car does not overheat?
Wiki User
∙ 8y ago
could be a faulty thermostat,or it could be a sign that your head gasket is about to blow ,or last of all your timing could be out of sync.
2from Inventus: It means your cooling system is funtioning properly. In a system having a coolant recovery tank, coolant in the radiator is always up to the brim, hot or cold. There is negligible or no air space. When coolant in the radiator expands sufficiently due to warming from the engine, it will squeeze past the pressure cap's bottom seal and flow into the recovery tank. (If no provision for such expansion was present, the expansion would rupture the radiator or your hoses.) Only coolant within the radiator is under pressure, and because of this pressure (together with the elevated boiling point that the "anti-freeze" permits), it normally does not boil. But once past the pressure cap's bottom seal, the overflow is at atmospheric pressure and therefore boils.This boiling is usually unnoticed after a short, i.e., local, trip because the cooler coolant already in the recovery tank quenches it. But after some highway driving the influx of more hot overflow heats up all the coolant in the recovery tank to the (unpressurized, i.e., "natural") boiling point.
As the engine cools when shut off, the contracting coolant in the radiator sucks back coolant from the recovery tank. Fluid in the recovery tank should never be below the "full hot" or "full cold" marks, lest air be sucked in.
-- BETTER ANSWER ==
Your cooling fans are not turning on. It is not normal for your overflow tank to boil like that. It is true that your radiator is overflowing into the reserve tank, but that means yourr adiaotor is boiling. Check for blown fuses or relays for your cooling fans. IF theya re fine. run your engine for about 15 minutes and drive. When you temp level is at normal operating temp open your hood with the engine runing and see if your fans are on. If they are, then you may have a bad thermostat or a plugged radiator, or a bad water pump. If the fans are not on, get your cooling fan switch replaced if your car has one. Check your temp sending sensor
---ADDED INFO--
I had the same problem. My coolant reservoir looked like it was boiling after the engine was hot but it was actually air going in. This happened when I replaced a new radiator and the fans turned on immediately when starting up the car (and never turned off) The wiring harness on my temperature sensor that is screwed into the radiator was not plugged in all the way. Toyota cleverly made this into a fail proof design where the radiator fans go on automatically and do not turn off even if the engine is cold and happens when it cannot detect the temperature sensor if it is failing or not plugged in.
Wiki User
∙ 8y ago
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What does it mean when the overflow tank is bubbling and the car overheat?
If the tank bubbles all the time the engine is running and is black dirty inside the head gasket has failed or a similar failure like a cracked cylinder head. If it only bubbling after the engine is overheated, the system needs to be checked for other failures.
Coolant fluid bubbling in overflow tank?
thermostat or blown head gasket....
What does it mean when the overflow tank is bubbling when you start the car?
Might mean you have internal engine damage like a blown head gasket. You need to get this professionally checked.
What does it mean when coolant in overflow tank is low and is leaking antifreeze from that side of the car?
The overflow tank is either cracked or its overheating and leaking from the cap
Can a gas tank overflow if it is not full?
A gas tank can indeed overflow if it is not full. A gas tank can overflow if the pressure inside of it is too high.
Why does a 2001 XLT overheat when ac is on?
I was having the same problem with my 99 explorer. What I discovered was that the overflow tank for the radiator was empty and was causing a false reading by the temp gauge.
How do you take a radiator cap of a 2000 Oldsmobile silhoutte?
Do not take a radiator cap off. Fill from the overflow tank or you will add air to the cooling system and it will have to be bled off or your engine will overheat.
What would cause a bubbling noise in a well pressure tank?
A bubbling noise in a well pressure tank is a sign of a hole in the tank. It means that air is getting into the tank and causing air to bubble through the water.
What does it mean when the overflow tank is bubbleing on 89 Chevy camaor 350?
You are most likely overheating.
What is that bubbling noise coming from your gas tank?
It is not common to hear a bubbling noise coming from you gas tank. It may be that your gas tank is too hot. You need to stop your vehicle and let a professional look at it.
Why does antifreeze surge in the overflow tank of a 99 Chevy Suburban?
Engine overheating will cause the anti-freeze to surge into the overflow tank. A blown head gasket will also cause the anti-freeze to surge into the overflow tank.
Why did the liquid in your overflow tank turn brown?
Rust from your cooling system is flowing back into the overflow tank when the motor warms up.
