‘It’s a myth’, warns mechanic about turning off AC before killing engine – and says leaving it on can help avoid smells

AN AUTO repairman has informed drivers why a widely believed practice is actually just a myth.

The YouTube creator is a Toyota Master Diagnostic Technician, according to his account.

In a video he shared on the platform, the mechanic known as The Car Care Nut (@TheCarCareNut) addressed the myth that drivers should turn their A/C systems off before cutting off their ignitions.

The mechanic said that cars made before the 1990s were made with "ancient electronics'

The YouTuber said that drivers don't have to turn off the A/C in modern cars

Screen text the creator added to the video read: "Should you turn off your car A/C before shutting it off?"

"Otherwise it'll cause damage," the creator said in the clip.

"That's what the myth is folks. If you own a very old car and when I say very old car, something before the 1990s, that's possibly the case."

He said that's "because of the ancient electronics that they had" at before the 2000s.

"But anything 1990s and now, basically any car with computer controlled HVAC or computer-controlled engine management system, you don't actually need to do that," the mechanic explained.

So, he said having to turn off your A/C system in your vehicle before shutting it off to maintain a good engine "is a myth in this case."

"So the idea of you should turn off your compressor or turn off your AC so the compressor would shut off is, you do not want an abrupt shut off," the auto pro stated.

"And then when you start the car that compressor is still engaged and that kind of creates a jarring effect in the A/C system."

This isn't the case with modern cars, the tech said.

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"When you shut off the car, the computer is actually shutting off that compressor or disengaging the clutch before the engine even comes to a full rest," the YouTube creator said.

"And when it restarts, which is the most important thing, it won't allow the compressor to come on until the engine is idling and it sees that things are safe then it kicks on the compressor."

The mechanic explained that many newer cars "actually don't even have a compressor clutch."

"They have a variable compressor that doesn't even have a clutch," he said.

"So that really takes that whole myth out of the window."

The mechanic additionally let viewers know what he advises drivers do "instead of worrying about shutting off your AC."

"If you have a car with auto AC that is modern, use it because there's so much logic built into that automatic mode that'll actually do a drying cycle when you shut off the car," the technician informed viewers.

"Some cars will actually turn on the fan to drive the evaporator because leaving that moisture there not only will cause smells, it actually cause evaporator leaks over time."

The post has been viewed over 300,000 times.