
What are the common symptoms of a bad AC compressor?
- AC system blows hot air
- Broken suction lines
- Loud noises
- Burning rubber smells
- Moisture leaks
- Compressor clutch is not moving
- Excessive wear on your auxiliary drive belt
Ever got into your car on a hot day, and been disappointed to find that your AC system just can’t seem to get your car cool enough?
Unfortunately, this insufficient cooling might not just be a nuisance. It could be a key indicator that something is very wrong with your car’s AC system.
That said, there are lots of components included in this system, so pinning down the problem can be a bit tricky. Luckily, Roberts is here to help. Here are the common symptoms of a bad AC compressor, and what they mean for your car:
AC system blows hot air

The whole point of turning on the AC in your car is to get cold air to come out. But, you might find your AC putting out warm or even hot air instead. This is a telltale sign of an AC compressor failure and usually happens right before this component dies out completely. So, if you notice that the air coming out of your AC vents is warmer than usual, then it’s time to get your car checked.
Broken suction lines
Another possible cause of hot air coming out of your car’s AC (but still connected to problems with your AC compressor) is a blocked or broken suction line. This prevents the car’s system from pumping enough refrigerant, which leads to hot air flow.
You can fix this problem with a quick trip to the mechanic, where a repairman can help you unblock the suction lines. However, if the line is broken, then it will need to be replaced.
Loud noises
If you start to hear some strange noises when you turn on the AC in your car, then it might also point to problems with your compressor. This is because, once this part starts to fail, it might make grinding or whining noises when your AC is turned on. These sounds are the result of the compressor’s internal components, such as its bearing, going bad.
To check if your AC is the source of these noises, simply pay attention to what happens when you turn it off. If the noises go away, then they’re not caused by a problem with your AC.
Burning rubber smells
In some cases, you might notice a burning rubber smell coming from your engine bay when you turn on your AC. If so, then this means that your AC compressor is seized and that the attached serpentine belt is spinning on the AC compressor pulley.
In simpler terms, the burning rubber smell is coming from components in your AC system rubbing too quickly against each other. Left alone, this will cause the belt to snap off quite quickly, so it’s important to act fast once you notice this smell.
However, if this smell is something that has been around your car for some time, then it is likely that something else is causing it.
Moisture leaks

Your car’s AC compressor is connected to a refrigerant line, which serves the purpose of pressurizing the contained refrigerant to help it cool down. Over time, this might wear down the bearings, which could result in leaking refrigerant.
This typically happens around the shaft seal, hoses, o-rings, and gaskets of your compressor. As it may be hard to spot on your own, you might need the help of a professional.
Compressor clutch is not moving
Just like a manual transmission, your AC compressor also uses a clutch. This clutch is connected to your vehicle’s engine and is used to draw power toward your compressor.
That said, this clutch is only used when your compressor needs power. If it gets stuck, then your compressor will not work because it won’t be able to get any power. If this happens to you, this means you need to replace the whole AC compressor, as the clutch itself can’t be replaced alone.
Excessive wear on your auxiliary drive belt
If you had to replace your auxiliary drive belt recently, but have also noticed that your new one is experiencing excessive wear, then you should check out your AC compressor — specifically, its pulley.
This might be a sign that your AC compressor’s pulley is beginning to wear out. When it does, it develops excessive movement in its bearings, which causes the pulley to go at varying angles while your car is running. These erratic movements will eventually snatch or grab at the auxiliary drive belt, and result in excess wear.
To determine if this is what’s happening to your car, remove the auxiliary drive belt from the AC compressor. Then, run your AC, and check again to see if the pulley is running at various angles. If so, it’s time to consider an OEM replacement.
In some cases, you can have the pulley changed without having to purchase an entirely new unit — but this depends on your car’s model.
Key Takeaway
Your AC is an essential part of your car — so knowing the common systems of a bad AC compressor for every car owner. Knowing these signs can help you quickly fix any issues with your air conditioning system before it becomes a costly problem!
Looking for replacements for your AC compressor? Roberts AIPMC is the top OEM auto parts manufacturer in the Philippines, and can quickly get you the parts you need. Contact us today to get started!