Skip the auto shop - Our mechanics make house calls

Q: Coolant reservoir overflows while air conditioning is running

asked by on

Car doesn't overheat but my coolant reservoir tank overflows while I have my a/c running. Why is this happening?

My car has 55000 miles.
My car has an automatic transmission.

Hello, A few different items can cause the coolant reservoir to overflow. If this is going on while the vehicle is not overheating, it is a bit less common.

The most likely causes would be a failure of one of these components:

When the AC is on, it puts a slight strain on the vehicle, which takes up some of the available horsepower.

A qualified Technician such as one from YourMechanic will be able to diagnose your coolant reservoir tank overflow fault and perform any repairs required.

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: How much does it cost to replace the coolant lines and the upper/lower oil pan gasket?

Billing question sent to CS for the cost to replace the coolant hoses by the turbo and the engine oil pan gasket.

Q: Flashing service engine light

If the check engine light starts flashing it can be for many different reasons and all of them can be serious causing the catalyst to get damaged and exceed emission out put from the engine. You could have a misfire...

Q: How do I use voice recognition to re-dial?

It is very easy to use voice recognition to re-dial a number in the infotainment system. To do so, press the voice command button, which will respond with “Ready”, followed by a tone. Following the tone, say “Re-dial”. The system...

Related articles

P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...
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...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.