Skip the auto shop - Our mechanics make house calls

Q: Frozen water in the reservoir instead of antifreeze

asked by on

I forgot to put antifreeze back into my reservoir and the water froze up once the temperature dropped. What's the fastest way to melt the ice? And will there be any serious damage?
My car has an automatic transmission.

Hi there:

Most of the time, when the coolant overflow reservoir freezes up due to water being put inside, it can cause cracking; since they are typically made of plastic. The best thing to do is to remove the bottom return line from the reservoir and flush it with room temperature water until the ice is completely removed. Once that’s been done, replace the overflow hose, fill up with water first to check if there are any leaks. If it does not leak, flush all water from the reservoir, and completely flush the radiator fluid from the system. Refill with 50/50 ratio of coolant to distilled water. If the reservoir leaks, you’ll have to replace the coolant overflow reservoir.

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: new spark plugs and wireset... difficulty Turing my car on. it turn on then it turn off

Hello, thank you for writing in. Considering that you just had work done to the ignition system, there needs to be an inspection of that first. Start with the new ignition cables (spark plug wires) that were installed. Make sure...

Q: Cabin fans not functioning properly.

Hi there. If the blower motor is coming on and you can hear it change speed but the air does not change then you may have a restriction in the air ducts. If the blower is not turning on or...

Q: Any suggestions for an intermittent starting issue?

Assuming no air leaks and/or EGR system problems such as a stuck open valve, if your car won't start without spraying a volatile, flammable substance (starter fluid for example) into the intake, that means there is a problem with the...

Related articles

P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the...
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...
P2103 OBD-II Trouble Code: Throttle Actuator Control Motor Circuit High
P2103 means there is a fault with the throttle actuator control motor circuit, likely due to a defective electrical component or part.