Moldy smell from AC at startup

ANSWER : If you have detected a refrigerant and oil mist in the cabin, then an evaporator "area" leak is likely. However, any time there is one leak, the entire system should be pressurized (whether pre or post repair) and tested for leaks in order to ensure trouble free operation. To request diagnosis and repair of your system, please use YourMechanic’s a/c diagnostic service page and the responding certified mechanic will get this resolved for you. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.

ANSWER : Hi, thanks for writing in. I’d be happy to provide some insight. The smell you are getting may be a small amount of water that sits in the air conditioning system. After you shut it off, it will start to grow mold. As soon as you start the car and turn on the AC, you will have this water evaporated and blown into the passenger compartment. I recommend looking in the cowl area under wiper arms at bottom of windshield to see if there are any leaves or debris that may grow mold and have it removed and area cleaned. This is where your AC sucks in out side air. Make sure to use recirculating air so you recirculate the inside air and use less outside air.

If you would like help, consider having an expert automotive technician from YourMechanic come to your home or office to inspect and diagnose this issue for you, and make or suggest any repairs as needed.

ANSWER : Hi Allen. By far the best way to have your AC system correctly diagnosed is by having an AC inspection completed first. By having one of our professional mobile mechanics come to your location to diagnose the issue correctly, it significantly minimizes the mistakes in completing the wrong service. In your case, the issue could be as simple as needing to have the AC system recharged, or there is an existing leak that needs to be repaired before refilling the refrigerant. Best economic bet is to have the AC inspection completed first.

ANSWER : Hello, thank you for writing in. The best way to remove a moldy smell from your vehicle’s air conditioning system is to replace the evaporator. This is a very time consuming and expensive repair, but is the only way to fully remove the mold. I would recommend enlisting in the assistance of a certified professional to have the evaporator replaced as the dash must be removed in most cases. This could result in many screws and bolts missing or in the wrong place. It is also important that the air conditioning system is evacuated prior to replacing the evaporator to ensure that no refrigerant is released into the atmosphere. If you find that the mold is at a more reachable place, you may be able to get rid of it on your own. Here at YourMechanic, we can have a technician come to your home or office to inspect this smell for you, and make or suggest the necessary repairs.

ANSWER : Hi there. It is very difficult to "guess" as to the cause of a smell like you’ve described without being their to inspection the car personally. I would highly recommend having a professional mechanic complete a smell in the car inspection; especially if you believe it to be an electrical short.

ANSWER : Hello, thank you for writing in. Although the pulley is still spinning, the compressor has likely failed. If it is not properly regulating pressure in the system, one of the first signs is a warm air conditioner. Considering yours is not cooling off, the pressures are not correct. If you believe the compressor is working correctly, you may want to check for a clogged line before replacing it. Keep in mind, a blocked line has likely put extra strain on the compressor, and may cause premature failure. For more help with testing or replacing the compressor, contact our service department to schedule an appointment.

ANSWER : Hi There,
As you know, your car has a cabin filter that serves to filter the air that is introduced to the cabin inside the vehicle. The best way to remove your cars interior ac odor is to use a cleaner that uses enzymes. Enzymes in cleaners kill odors at the source and completely kill the smelly substance material and therefore stopping the a bad smell. To get rid of the smell, try the following: First turn on the ac to full, make sure the “recirculate” button is not on, spray a large amount of cleaner with odor killing enzymes into the EXTERIOR air intakes that are located just below the windshield wipers, let the car run for about 10 minutes with the ac on, after 10 minutes turn off ac and spray the cleaner into the ac vents on the INSIDE of your car. After doing all this, let the car sit for 20 minutes turned off and windows rolled up. Then repeat if the smell is still in the car. By doing this you are killing the bacteria or mold in the car ac vent ducts and also the evaporator mold that may be present.

ANSWER : There are different possibilities that could contribute to the plastic smell. The smell could be caused by a coolant leak, an electrical issue, the A/C compressor overheating, or simply an outside smell.

Sometimes, plastic bags tend to get stuck to the exhaust system and melt. If you had the vent on for outside air, you probably smelt a bag burning, or some ambient smell. If you had the recirculate button on when you experience this smell, then it is time to change your cabin filter. The dust on the cabin filter will make a burning smell as air is passed through it. Plus, if the filter is dirty, then the evaporator will not function correctly and also causes the a/c to not blow as cold as usual. If the filter is good and clean, then it is possible that the a/c system has sprung a leak and you are smelling the refrigerant.

If you need further assistance, then seek out a professional, such as one from YourMechanic, to help you diagnose the cause of the warm a/c and plastic smell from the vents and replace the air filter, if needed.