Skip the auto shop - Our mechanics make house calls

Q: My car is getting overheated, replaced the water pump, but coolant is still running out.. After the car warms a lil..

asked by on

Coolant is running out the car, replaced the water pump yesterday, coolant still flowing out, after the car is crunk about 5min..do you think I need a thermostat?? Or what could be the problem

My car has 128000 miles.
My car has an automatic transmission.

A: A thermostat is a good first step with over...

A thermostat is a good first step with overheating issues, usually because it’s inexpensive and easy to replace. So it’s always good to eliminate that as a possibility, but I think you may have more problems then that. I presume you mean that coolant is running out of the overflow tank. This happens because of excessive pressure in the cooling system. It can happen if the coolant is low, because air pockets in the system cause hot spots where the remaining coolant will boil. It can be difficult to get all of the air out of the system so that’s a possibility especially since you just changed the waterpump. It can also happen if there is combustion pressure leaking into the cooling system as it does with a bad head gasket.

When you change the thermostat, find a heater hose or some other small cooling hose near the top of the engine and disconnect it. Refill the engine with 50% diluted coolant until coolant runs out of the hose you disconnected, then hook it back up. Run the engine with the defroster on maximum until you feel heat coming out of the dash vents, checking the coolant level periodically. When you feel good heat, you know the engine is full. If you continue to have a problem, contact YourMechanic and they will send a technician to your home to diagnose your cooling system and tell you what you can do.

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・Fair and transparent pricing

Get a quote

What others are asking

Q: Are Jaguars generally reliable?

Hi there: To be completely honest, I've never known a Jaguar owner who hasn't had their car in for service at least three times during ownership. They are notorious for faulty electrical systems, fuel system issues and transmission problems. Unless...

Q: The key won't turn in the ignition

There are several things that may be causing these issues. One place to start is the shift lever. There is a sensor that only allows the vehicle to be started if it is in park or neutral. Try shifting the...

Q: Overheating car

Hi there. Many components make up your cooling system. If any of these components are not functioning properly it will cause your vehicle to overheat. If your vehicle is not leaking any coolant, chances are that your radiator fan(s) are...

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...
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...