Hi,

As part of my 2010 SD4 HSEA purchase the dealer (non LR) said they replaced ALL of the parking sensors - one on the rear was obviously gone.

3 days into ownership and they aren't working again. Looking at the front ones, one looks a bit faded so I suspect it is the one that's gone so maybe they only replaced all of the rear ones.

They seem particularly keen on pressure washing the car (paint issues are another thing they need to fix), and I notice the manual says to keep the washer away from the parking sensors.

Other than that likely cause, I had a towbar fitted but they were working after that was done.

Are they known for being flakey? Or is it just coincidence they've gone so soon after being 'fixed'?

Three days in from a dealer? Take it back, get them to sort it. Regardless of whether LR sensors are ‘flakey’ if the car’s sold with them you have to expect them to work. More so if the dealers been pressure washing them against advice

The sensors don't like pressure washers and they sometimes fail due to heavy rain or wading a bit too deep but they usually start working when they have dried out.

What works for me is holding a paper towel just below each sensor, then squirting WD40 directly on to it.
Dispels any water present.

Not had a minutes problem with mine in 12 years of ownership. Silver 2009 HSE

Quite possibly a loom problem had that with mine and a disco 3
Especially if they are intermittent
Like said above they don't like water but they are fine once dries out