2015 Volkswagen Beetle - Engine sounds and AC

My engine is racing more now when I use the AC and when I turn car off it still runs a little and I turn off AC

My only guess is that there is a vacuum leak somewhere in the AC system. This would explain the running on (it’s called dieseling) after the ignition is turned off.

Are you sure it’s the engine and not the cooling fan or fans? In most of the country right now, the cooling fans will be cranking away at top speed.


I was wondering the same thing. Is dieseling even a thing any more with fuel flow electronically controlled? I guess a bad ignition switch might do it but I doubt that’s what’s happening.

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I think that the OP is hearing the electric cooling fans running, and misinterpreting that noise as engine noise.

Note to OP:
During very hot weather, those fans need to run for a couple of minutes after you shut the engine off.
If they didn’t, your engine would be damaged.

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