When my air is on I hear a noise from front to back on the passenger side of my 2012 Dodge Caravan minivan with 137,000 kilometres on it. Can you provide some ideas? — Bob
Noises will travel through the chassis of any vehicle; attempting to determine their source can prove to be challenging.
Have a helper travel with you sitting in various positions within the cottage, listening and noting where the sound appears loudest.
In the drivers’ seat, you’re nearer to the front HVAC unit and some sound emanating from it ought to be evident.
Many Caravans do also have a back HVAC unit situated just above and behind the rear passenger wheel. Toggle the rear AC off and on, listening for any perceptible changes.
AC systems generally can emanate an assortment of noises, anything from a blower motor which screeches because of a failing bearing or a flutter when debris finds its way to the fan.
An air blend door actuator changes the air flow inside the cottage and can occasionally get stuck in 1 position. When frozen, the engine trying to open or close the blend door can do this perpetually, causing a clicking sound.
The air-conditioner’s expansion valve changes the state of the refrigerant from a liquid into a vapour; an occasional hiss from this unit is deemed normal.
A faulty valve or a system running low on refrigerant may lead to an expansion valve which makes erratic, strange sounds.
Lou Trottier is owner-operator of All About Imports in Mississauga. Have a question about repair and maintenance? E-mail , putting “Lou’s Garage” in the topic area.
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