I’ve been getting a rear offside drop on my 4.2SC. Changed the ride height sensor and did both air bags for good measure, but still got it.

The suspension works fine and goes up and down etc so wondering if it’s possibly the rear valve block ?

Yeah could be.
While at ride height, Remove the fuse from under bonnet

Leave over night proves it’s an air leak.

Rear block a pain to change, but u can get seals off eBay

Thanks Andy - fuse pulled. It happened soon after having the compressor renewed. The Indy that did it said that it couldn’t be anything to do with the compressor change.

Got a rebuilt rear valve block sat in the workshop, so we’ll see what the fuse pull does overnight.

Went to look at an 04 L322 today on a whim. Made me realise just how good condition my car is in.

Dropped again overnight with the fuse pulled.

Will get the pipe changed and see what transpires.