Hello all! I have a 2001 Disco 2 SE7 with ACE and I just had the rear air springs converted to coil. Ive noticed in the past few days sitting at idle at a red light, every 10-15 seconds, a sort of puffing/maybe grinding? sound comes from the truck. A/C was not on and I was in D at all the stop lights. I don't really 'feel' it vibrating in the truck but you can sure hear it. Anyone have an idea of what that might be? Thanks!

 

Ace pump cycles about every 10-15sec with a very distinctive sound.

 

Ah! Ok so that could be it. Does it cycle the entire system? I’ve never seen any drops on the ground so nothing is leaking after the sound and the sound only lasts like 1-2 seconds.

 

Sound is totally normal when the engine is running.