Skip the auto shop - Our mechanics make house calls

Q: Smell coming from A/C vents

asked by on

There is an odor in my car that comes in through the vents of the A/C system. There has been a leaking radiator, but it was replaced. That ‘had’ been a source of one odor, but now there is a 2nd one and it is literally giving me headaches. At times, the smell is rather metallic and like hot exhaust fumes. Yet, it also smells like hot fluid similar to power steering fluid or anti-freeze. The dealer did a pressure-check on the cooling system and reported to me that it is not a heater core leak. I replaced the fresh air filters. Around the filters, I thought there was a gap and leak, but they appeared fine. The smell is only from the driver’s side a/c vents. When the air flow is on low, the smell is more pronounced. I crack the window or open the sunroof. I had also thought that it might be the exhaust back-drafting into the car. The dealer has not helped me one bit, despite the expense! Can you give me suggestions on the cause of this problem and how do I solve it?

It sounds like you have a leaking heater core inside the evaporator housing and would need to have it replaced. If you have the heater bypassed then you will not have heat inside the car and the temperature control will only work in the cold settings. I recommend having the heater core replaced. You can have this issue verified by a qualified mechanic, such as one from YourMechanic, in order to diagnose the car’s smell and let you know what should be done.

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: Engine out of time - 1997 BMW 740iL

Hello there, an improperly timed engine can result in serious damage to your 1997 BMW 740iL. When the timing is not set properly, the risk is if the timing is far enough out of the valves can come into contact...

Q: What could be wrong with it

It sounds like you are getting a misfire in one or more cylinders. You should have the engine checked for good ignition spark plugs and wires. You may need to replace the spark plug and wires to see if it...

Q: bogging

Hi, thanks for writing in about your 1999 Mitsubishi Eclipse. I would recommend that you open your air filter to make sure that it is dry. If you drove your car through a car wash while the car was on...

Related articles

How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
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.