Rumbling noise when A/C is on

[sdeni]

Hello,

I have recently noticed a rumbling noise coming from under the middle back seat in 2015 Mazda 3 Sport GS. After initial investigation, the noise starts when I turn on the A/C, and stops a few seconds after it's off... It happens in situations when the car is idle in park or just stopped on traffic lights; can not confirm if it is present when I am driving (might be too quiet).

Is this issue familiar to anyone here?


Thanks!

[morganc]

The A/C compressor is likely causing the engine to bog down at idle (think about how much your car shakes and makes bad noises if you almost stall a manual tranny car.) This bogged down idle speed is transmitting noise through the exhaust system (hangers) and voila.

[Superchargedx]

Could be the ac compressor itself... They are common on first gens!
Sound travels in funny ways in a car,can be deceiving

[Zotaga]

Hello,

I have recently noticed a rumbling noise coming from under the middle back seat in 2015 Mazda 3 Sport GS. After initial investigation, the noise starts when I turn on the A/C, and stops a few seconds after it's off... It happens in situations when the car is idle in park or just stopped on traffic lights; can not confirm if it is present when I am driving (might be too quiet).

Is this issue familiar to anyone here?


Thanks!

Check your muffler hangers.. sounds like one of them may be broken.. sounds stupid but I have the same type of rumbling noise and that's my problem hahah.. in the process of fixing the hanger situation.