Need to know what this buzzing is please


....02 vogue when i start it up i get a buzzing from the rear for about 15 to 20 seconds will also do it at random times during the day
When i bought it the guy said its the lpg pump in the rear!! but still makes the noise when im running on petrol.

Im worried i have a leak in the rear suspension and its the compressor is working pumping it back up???????

This is my 3rd range rover and i have not heard it before?

Help

the compressor is under the spare wheel, start the car up and listen to the compressor to see if its that 2002 td6 vogue, 06 supercharged facelift

It's your Air Suspension pump. Your LPG doesnt have a pump.

However, if you have LPG then the reason you can hear the air suspension pump is because it will have been re-located to make room for the tank.

Your suspension levels all of the time so it will run every few minutes, this is no cause for alarm.

Dan 

Thanks was getting a tad worried.