Q: AC makes hissing noise and doesn't blow cold
I purchased a pre-owned Bravada. The car has an issue with the AC not working correctly. When I turn it on, it doesn't blow cool air at all and it starts making hissing noises. What could be the problem?
Recommended Services
| Coolant is leaking Inspection | $94.99 - $114.99 | Get a Quote |
The hissing noise is due to the A/C evaporator being starved of enough refrigerant. You will need to have refrigerant and dye added to the system and the hissing will go away. Then use a leak dye light (black light) and check to see where a leak is and fix as required. If you want to have this looked at for you, a professional from YourMechanic can come to your car’s location to add refrigerant, detect any coolant leaks, and perform any repairs that are needed.
The statements expressed above are only for informational purposes and should be independently verified. Please see our
terms of service
for more details
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
What others are asking
Car starting and dying
Hi. Replacing parts without diagnosing can get expensive very quickly. The carburetor needs to be adjusted properly before installing (idle screws 3 1/2 turns out, throttle stop barely cracked) and the insulator gasket has to be the correct part. Many...
Engine knocking
Knocking in your engine, also described as pinging, can mean one of several problems. Some may be easily fixed while others may indicate major damage. The knocking sound often occurs when the fuel and air mixture is incorrect, which causes...
New battery; car won't start
Hello. If the car is not starting after a battery replacement then you either have a bad connection at the battery or it is possible that the programming in the computer got corrupted when the voltage was lost. This can...
Trouble accelerating
The boots may of not been installed correctly and/or the axle shaft was not installed all the way into the joint after removal leading to the clip not engaging the joint and binding the differential in the transmission. This is...
Car Window will not roll up
It sounds like your window switch (https://www.yourmechanic.com/article/symptoms-of-a-bad-or-failing-power-window-switch) may be faulty. If you hear the motor try to move (https://www.yourmechanic.com/article/how-to-fix-common-electric-window-issues-by-ryan-carter) the window when pressing down but no noise is heard when pressing up, its most likely the window switch. If you...
transmission (ax4n) is not going into overdrive
You will need to have the transmission tested to see if the transmission solenoid for the torque converter lock up solenoid is stuck or bad. The transmission fluid should also be checked (https://www.yourmechanic.com/services/transmission-fluid-service) to see if it is full of...
When parking lights activate, left turn signal independently stays on
Hello there, thank you for asking about your car. If the turn signal stays solid on the dash instead of blinking, that typically indicates a failed bulb. If the bulb is not the issue, check the connector at the turn...
what sends signal to a TPS sensor
Hello, thank you for writing in. The throttle position sensor does not take inputs from anything, but instead it acts as an input to the ECU (the main computer). The ECU then uses it for engine performance. The sensor's resistance...
1999 chevy K150 suburban electrical problems
Hello, thank you for writing in. There are several components that will attribute to electrical issues like this. Generally speaking, when you have issues with several electrical systems at once, and not just one or the other, the charging system...
Related articles
Does Running My AC in the Summer Keep My Engine Cooler?
When When you engage your air conditioning in your car, it is usually summertime and hot outside. Air conditioning serves to remove heat from the inside of your vehicle by circulating a refrigerant through the evaporator core in your dashboard,...
Signs of a Bad or Failing AC Compressor Relay
Common signs include inconsistent cooling, not hearing a click from the compressor turning on, and no cold air.
How to Get an EPA License as an Automotive Technician
Automotive technician jobs require an EPA certification to learn how about the environment while repairing automotive air conditioning systems.
Browse other content
Cities
Maintenance