Skip the auto shop - Our mechanics make house calls

Q: A/c check engine light on

asked by on

My wife was driving home with the a/c on. The a/c quit working, the check engine light came on, steam or fog type substance (she wasn't real sure which one) started coming from the a/c vents & the temp gauge went all the way to high & the car died. She said there is anti freeze everywhere. What could this be?

My car has 119000 miles.
My car has an automatic transmission.

A: If there is antifreeze inside the passenger...

If there is antifreeze inside the passenger compartment a hose to the heater core and/or the heater core itself has developed a leak. If the antifreeze has instead sprayed into the underhood area, the leak would be in the engine compartment.

The fact that you state it "was coming from the vents" is suggestive of an inside the vehicle passenger compartment leak, although it is possible that an external (under hood) leak spraying forcefully near the cowl fresh air intake could entrain antifreeze into the A/C air intake if the A/C was set to outside air (i.e., not recirculation).

At any rate, the problem is resolvable and probably limited and thus you should contact YourMechanic who can diagnose the leak and put your car back together. If antifreeze got into the passenger compartment of the car, it will have to be cleaned by the way. Antifreeze is not a healthy compound to be breathing in.

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: Car is burning antifreeze

If your car is overheating, smelling like coolant, and always in need of coolant, then those are signs that you may have a coolant leak somewhere. The smoke you are seeing may be antifreeze leaking out onto hot parts of...

Q: Engine knocking and engine light on

Hello. If the Check Engine Light is on, then it would help to know what codes are coming up. The computer codes would help a mechanic find a starting point to determine the problem. From the description of the problem,...

Q: Does the AC Use a Lot of Energy From the Engine?

Operating the A/C system definitely demands more energy from the engine and electrical system. Whether it’s a lot depends on how hot you are and how much you’d like to be cool! Seriously, it can require approximately 5 horsepower...

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...
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 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.