Skip the auto shop - Our mechanics make house calls

Q: Water coming out of overflow tank

asked by on

My car started over heating bad so I changed the radiator and cap, water pump, thermostat and lower radiator hose. It was still overheating so I did a head gasket job on both heads. I got the full gasket kit and replaced all the gaskets. I wired my fans so they are always running when the key is turned on. But now when I drive and put the car in park and turn it off water starts flowing out of the overflow reservoir. What could be the problem?

My car has 18000 miles.
My car has an automatic transmission.

A: The coolant in the engine has the job of re...

The coolant in the engine has the job of removing heat from the engine and releasing the heat by way of the radiator. The coolant is circulated by the coolant pump. If there is a pressure created internally other than the coolant system creates, it can prevent this flow. If coolant is coming out of the overflow it is overheating. Coolant system failure can be a slow process until the signs are hard to ignore. Running the coolant fans are just masking the problem.

Antifreeze has a time limit before it needs replacing, five years is the maximum time allow. If the vehicle has been overheated to a damaging point it can crack the engine's cylinder heads causing a pressure to enter the coolant system. This will stop or slow the flow rate of the coolant pump which will cause a overheating condition. There are tests that can be preformed to confirm this. I'd suggest getting some assistance from a certified technician, such as one from YourMechanic, to diagnose your overheating issue and make the necessary repairs.

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

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Save up to 30%

Get a quote

What others are asking

Q: Only getting luke warm heat out my vents

Hello. The heater is a part of the vehicle's cooling system and uses the same fluid. The first thing I would do is check to make sure that the system is properly filled and bled. If any air gets trapped...

Q: Oil draining when I start my car.

If this is a sudden and unexpected problem, then your oil filter may have a leak or has become loose. The vehicle will have to be checked in person by a mechanic to see if it is just a leaking...

Q: Power windows slow to close

There is a high failure rate with the electric window motors on your particular vehicle. The electric motors will need to be replaced in order for the windows to operate smoothly and efficiently. Replacing the motors requires removing the interior...

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...