Car Interior in Smoke or Vapour

Smoking A/C Compressor

You are cruising in your car and noticed smoke spewing from the vents when the A/C is turned on. However, there is no smell. Should you put anti-freeze? Or should you put your car in the shop? What does a smoking A/C compressor tell you?

Blown Heater Core

A smoking A/C compressor can mean several things. Did you pick up a sweet coolant smell from the vents? If the answer is yes, it could mean that you are low on coolant, and the smoke is related to a blown heater core. If you are wondering what a heater core is, it is basically a radiator. It is the area where hot engine coolant runs through to heat up the car’s interior. Next, there is a fan blowing over the heater core, which allows the air of your car’s interior to be heated. If the heater core becomes faulty and leaks coolant, smoke is created when you turn on the A/C.

What if the smoke was odorless? If there was no presence of any sweet smell, you can rest assured that your A/C is working at 200%, creating an icy fog. This happens from time to time, and is affected by the humidity levels outside.

Just make sure that you keep track of the coolant level. If you continuously lose coolant, it is about time you get the heater core checked out.

Faulty Compressor Clutch

If the part that was smoking is the compressor clutch, it is a clear sign that you need a new compressor. Faulty compressor clutches could be the result of an overcharged system. If it was the case where the compressor should not come on, reasons might include:

  • The compressor clutch is shot
  • The compressor belt could be slipping very badly
  • The solenoid responsible for engaging and disengaging the clutch could be bad

While it is possible to replace just the clutch, it will be a lot easier if you replace the compressor. The entire procedure will only take 30 minutes. After the replacing the compressor, you need to remember to discharge and recharge the system. It is a good practice to also replace the line dryer each time the system is opened.

Depleted Oil

Smoke is also a result of an A/C system being depleted. It is burning up because it needs an oil charge. In this case, you should avoid running your A/C for the time being. If you continue running it, you will burn your compressor out completely. In that case, you need to get a new compressor – possibly worth hundreds of dollars per unit.

You may wish to purchase a recharge kit and a pressure gauge for a quick DIY project. Don’t worry as the task is easy to perform. There will be instructions right on the cans. Your job is to basically attach the hose fitting to the low pressure side of the A/C system (it is the fatter pipe) and then turn your car on again. The next step is to slowly charge the system until the pressure gauge indicates that you have reached optimal levels.