Q: My air conditioner blows warm when idle, looses coolant and starts to overheat.

asked by on

My explorer started blowing warm air when idling. A week later, it was blowing warm air at high speeds and the engine got all the way hot. So I checked it out and the coolant and the oil was low. I filled up the coolant and added oil, and the next day had an oil change and the ac worked fine for a week. Well it started back. It hasn't got hot on me yet and the oil is fine but ac blowing warm while idling and i'm loosing coolant. When I got out of it today after driving awhile, the coolant was bubbling out from the overflow cap. What is causing this? The fan has resistance when trying to spin it and it seems to stay on from the time you cold start the vehicle. But if the fan clutch was stuck engaged then it wouldn't be overheating, right?

My car has 165000 miles.
My car has an automatic transmission.

Hi! I have a couple of thoughts that may help you sort out the issues with your Explorer. There may be separate root causes of the issues with the air conditioning system and the cooling system.

The first thing I would do is a pressure test on the cooling system. This will help to identify whether there are any leaks in the cooling system.

Something as simple as a faulty radiator cap can allow coolant to bubble over out of the radiator. I would just put a new radiator cap on it.

Your engine may actually have a blown head gasket. One of the symptoms can be engine compression leaking into the cooling system and over-pressurizing it to the point of pushing coolant past the radiator cap and out of the overflow. There is a testing tool that can can be helpful called a block tester. It is used to identify the presence of combustion gasses in the cooling system.

A qualified technician from YourMechanic can come to your home or office to inspect your AC system and recommend the best path to repair.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1,000 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
  1. Home
  2. Questions
  3. My air conditioner blows warm when idle, looses coolant and starts to overheat.

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: Vibrating and shaking after putting intake manifold gaskets

Oil leaking down into the spark plug wells can causes the plugs to short out to the cylinder head, yielding the misfire you are experiencing. Replacing your valve cover gaskets, the plugs, and cleaning out the spark plug wells, and...

Q: Air conditioning sometimes cold and then hot

Hello. When you get an AC system that is constantly changing temperature the most common cause is low refrigerant. If the system was filled within the last year then there may be a small leak that is causing this condition....

Q: I need a new thermostat and coolent flushed what is a fair cost to fix this

Hi there. If you had a low coolant light diagnosed through an error code, you should have a professional mechanic determine why the coolant was low. To get an accurate quote, please fill out a thermostat replacement request. Once we...

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...
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...
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.