As a Lexus repair shop, M & R Automotive near Menlo Park, CA, frequently diagnoses Lexus RX 350 AC problems. One of the most common issues we diagnose in the summer is air conditioning systems blowing hot air.
A properly working Lexus AC system needs sufficient refrigerant in the system. Sometimes it just needs to be recharged. If the system has sufficient refrigerant, we turn our attention to diagnosing other potential problems.
Refrigerant leaks are one of the more common reasons why a Lexus RX 350 blows warm air out of the AC vents. In a properly functioning automotive air conditioning system refrigerant circulates, which allows heat to move out of the passenger compartment.
A slow leak in something simple like a hose, seal or the condenser gradually lowers the system’s refrigerant charge and reduces performance. Depending on system pressure, low refrigerant also could prevent the AC compressor from properly engaging.
Another common AC system issue we see with the Lexus RX 350 involves the compressor control valve itself. The valve is designed to regulate the compressor operation and refrigerant pressure. If it starts sticking or responding slowly, the system may struggle to build the pressure needed to transfer enough heat energy to blow cool air.
In the hottest part of the summer, an RX 350 blowing warm air from the AC vents might be a problem with the cooling fan. With a problem like this the air conditioning might perform reasonably well while driving at highway speeds. Then it becomes noticeably warmer when you’re idling at a stoplight or sitting in traffic.
The electric cooling fan is designed to move air across the condenser. This helps heat energy to leave the refrigerant. If the fan doesn’t operate correctly, the system will start to struggle to transfer heat anytime the vehicle sits still. Once you begin moving and air naturally passes through the front of the vehicle, the Lexus RX 350’s AC system starts to perform normally again.
Sometimes, something as simple as a blend door actuator problem can cause AC issues in a Lexus RX 350. This simple temperature-control door is designed to direct air through the appropriate part of the HVAC system. Different temperatures blowing from different vents is the most common symptom of a problem like this.
Your Lexus RX 350 blowing warm air out of the AC vents doesn’t automatically mean the system needs more refrigerant. A leak, compressor control problem, a condenser fan failure or even a bad blend door could be the cause. M & R Automotive specializes in Lexus diagnosis, repair and service.
If your Lexus RX 350 is blowing warm air from the air conditioning in the heat of summer, don’t wait for the problem to get worse. Contact M & R Automotive to schedule an inspection and get your AC system ready for the next heat wave.
