Skip the auto shop - Our mechanics make house calls

Q: My car is spitting coolant from the overflow tank

asked by on

2004 Chevy Tracker started spitting coolant from the overflow tank. No overheating problems or leaks beforehand until now.

Without any warning, most of the coolant had blown out of the overflow tank. After allowing it to cool for a couple of hours, I refilled the radiator and overflow tank to recommended levels. Drove it another ~6 miles and it started overheating again. Opened the hood and found the overflow tank FULL and spitting coolant again.

The system appears leak free but obviously something ain't right given the symptoms. The coolant system was replaced four years ago after a collision with a deer and everything has worked perfectly since then. This just started today for no apparent reason. What's up with that?

My car has 160000 miles.

A: Hi and thanks for contacting YourMechanic. ...

Hi and thanks for contacting YourMechanic. Check the coolant strength to see what the protection is. A good protection will read 164 degrees Fahrenheit. Check the radiator cap to see if the seal is torn or if the release valve inside the cap has failed or is sticking open. A radiator cap can cause the system to boil and spit out all of the coolant.

If you have good coolant and the radiator cap is new, then the thermostat could be sticking causing your coolant to heat up too much which in turn causes the system to boil. To check if the thermostat is working, start up the vehicle when it is cold and watch the coolant temperature gauge. When the thermostat opens, the gauge will drop a little.

If the gauge does not show this, then, when the upper radiator hose gets hot, right after the thermostat opens, the coolant flows through the hose and you would be able to feel this. Plus, the hose will begin to get cooler as the coolant travels through the hose. If the thermostat was replaced and you still have a boiling issue, then the head gasket has burned on the engine.

If you need assistance, then seek out a professional mechanic, such as one from YourMechanic, to help determine why the car is overheating and why the coolant is boiling out.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Engine problems

If the engine is overheating then you will need to see if the upper and lower radiator hoses are both hot, but the lower one will be cooler than the top. This tells me the thermostat is open. If the...

Q: My engine's cylinder 5 is misfiring

Hello there. A cylinder 5 misfire is a common problem with your vehicle. There are a number of common causes for misfires, including the spark plugs, the spark plug wires, the cap and rotor, the crankshaft position sensor, vacuum leaks,...

Q: Do you have to remove the transmission on a 2003 Chevy Tracker with a 4 cyl. engine to replace the crankshaft position sensor?

Hi there. The crankshaft sensor is mounted behind the engine flex plate flywheel. The transmission and the flex plate flywheel needs to be removed to replace the crankshaft sensor. If you need help with a crankshaft sensor replacement, a certified...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
How to Avoid Back Pain in a Car
If you have back problems, sitting in a car for an extended period of time can be excruciating. Even without back problems, you could experience discomfort and soreness from...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...