What is the reason for the lack of hot air from the rear air vents in the Envision?
2 Answers
The rear air conditioning in the Buick Envision not producing hot air is due to the low level of coolant. Below are the reasons for frequent low coolant levels and the coolant replacement cycle: Reasons for frequent low coolant levels: Leakage in the engine usually occurs between the cylinder head and cylinder block, water pump housing and cylinder block, water pump impeller shaft seal, and the junction of the thermostat valve cover and manifold. Leakage between the cylinder head and cylinder block can cause internal leakage, while others manifest as external leakage. Poor circulation leading to rapid consumption can be checked by a professional technician. Note that coolant should be added only after the engine temperature has cooled down. Replacement cycle: Generally, coolant should be replaced every 40,000 kilometers. During the car maintenance cycle, as long as the coolant in the reservoir is above the minimum level line, there is no need to top up the coolant. Proper maintenance requires checking the coolant level in the external reservoir during every 5,000-kilometer service to ensure it is appropriate.
Last time I drove my friend's Envision, the rear heating suddenly stopped blowing hot air, which was really annoying. I figured there could be several common reasons: First, check the AC settings—maybe the temperature was set too low or the airflow mode was incorrect, especially since automatic AC systems can sometimes misjudge. Then, inspect if the rear vents are blocked by anything and try cleaning out the dust. If it's a system malfunction, like a clogged heater core restricting coolant flow, that would prevent hot air from being delivered. Or maybe the blend door actuator is stuck, not opening the pathway for hot air. Sometimes, the electronic control unit glitches, with faulty sensors causing the heating to fail. My approach was to first reset the AC settings to default. If that didn't work, I’d head to the dealership to let them use professional tools to check the cooling system and electrical circuits, avoiding further delays that could worsen driving comfort. Remember, regular maintenance can reduce such issues—like cleaning the air ducts every six months to prevent blockages.
