What is the solution for BMW 740 air conditioning not cooling?
4 Answers
The solutions for BMW 740 air conditioning not cooling are: 1. Appropriately reduce the refrigerant amount; 2. Check if the condenser pipe has dirt and clean the condenser; 3. Refer to the pressure gauge for judgment and perform system reprocessing; 4. If airflow decreases and system pressure and temperature become unbalanced, clean the evaporator or filter. Taking the 2019 BMW 740Li as an example, its front suspension is a double-wishbone independent suspension, and the rear suspension is a multi-link independent suspension. The 2019 BMW 740Li is equipped with a 2.0T turbocharged engine, with a maximum horsepower of 265PS, a maximum power of 195kW, a maximum torque of 400Nm, and is paired with an 8-speed automatic transmission.
I've been in the auto repair industry for many years and have seen numerous BMW 740s with air conditioning issues. The most common problems are refrigerant leaks or insufficient levels, resulting in weak cooling. You can check it yourself: after starting the engine, press the AC switch—if there's no humming sound from the compressor, it might be a compressor failure or an electrical circuit issue. Also, check if the cabin air filter is clogged, as excessive dirt can impair cooling performance. For high-end cars like BMWs, the complex control systems mean that faulty thermostats or sensors can also cause problems. I recommend starting with simpler checks, such as verifying if the blower fan speed is normal. When temperatures rise, a malfunctioning AC can be dangerous, increasing the risk of drowsy driving. Regular maintenance is the best strategy—cleaning the filter every quarter can prevent most issues.
My BMW 740 also had an AC breakdown last summer, leaving me sweating profusely. Later, I found out it was due to insufficient refrigerant pressure caused by a tiny leak in the condenser. I tried topping up the refrigerant, which worked temporarily, but the problem soon recurred, forcing me to take it to a professional shop for a thorough inspection. The AC system in this car demands high precision, and DIY attempts can easily go wrong. The lesson I learned is not to neglect the AC in daily use—test the cooling effect monthly and check it when the weather changes. Additionally, BMW's heat exchangers are prone to dust buildup, which improves after cleaning. Now, I always perform maintenance in advance to avoid suffering on the road.
As a car enthusiast, I've maintained the air conditioning system on my BMW 740 myself. When the AC isn't cooling properly, first check if the compressor is running: open the hood, start the car, press the AC button, and observe whether the clutch engages. If it doesn't move, it might be a faulty relay or fuse. Then check if the refrigerant level is normal. BMW's electronic control units are quite sensitive - minor faults can lead to major issues. I recommend DIY enthusiasts clean the condenser and evaporator, but be careful when doing so. Prolonged AC failure can compromise comfort; if this happens while driving, remember to ventilate the cabin and reduce speed. Regularly replacing the filter can extend the system's lifespan.
