I know, if we had a pound for every post about a rattle, knock or squeak in a p38 we'd all be millionaires, so to help you on your way....

I have an infrequent tap from the direction of the LH rear door or under the back seat. It sounds a bit like if you took a plastic handled screwdriver and tapped the chassis, or bodywork. It only seems to happen at low speed, less than 10 mph. It fairly often does it after slow braking, when the car's almost at a halt. Some times it does it just rolling along. Occasionally when I'm stationary, or if I turn the ignition off, but it's all low speed stuff. I have put the EAS up and down a few times to see if that had anything to do with it - seems not. I had the air con switched off, to be sure the clutch was not creating a phantom noise.

What moves almost randomly under the rear end of the car? I suppose I can check the rear calipers/ guide pins, but they were all thread locked anyway. something come loose in the fuel tank? I cd maybe check the exhaust mountings

exhaust heat shield?

grease your universals they may be just dry

I'd suspect exhaust mountings. The exhaust might move when the engine stops. Check right at the very rear too. One of my rear boxes is very close to the end of the chassis so could touch if it had shifted on the hangers.

Tnx, I'll take a look. I know that my exhaust comes close to the panhard rod, for example, and if I take a speed bump at high speed I can hear a bit of a clang. But, this sounds internal to something and is no louder window down versus window up, it will occasionally do it while the vehicle is stationary, so I was wondering if there's some electrical system active & doing something. If I am stationary on access height, then occasionally I can get it to do it by going to ride height - maybe something to do with the self-levelling. None of this happens over 10, perhaps 20, mph

I've also got a similar annoying noise.
It drives me bloody crazy

check your bushes ,they could be loose or worn, including shock rubbers, the only thing that moves when stationary.
get someone to drive it around so you can walk beside it and listen for the noise.

Personally I think mine is top damper rubber.
But as I can't get the bloody thing off I can't tell for definite.

:)

Could well be. I had a very slight knock from somewhere on the rear of mine a few years ago although that was suspension movement related but only noticeable at low speeds. Spent ages trying to find something loose with no joy until I took it into a mates workshop, got it up on a ramp and got his apprentice to keep bouncing the car by hanging off the towbar. Turned out to be coming from one of the rear shocks but not from a top or bottom rubber but from inside the shock itself. Somethng had obviously come loose inside as once it was off there was about half a millimetre of free movement..

Ah well, I hope mine's easier to find than that.... retorqued the shocks today, put another few lb ft on them, but as if the car sensed my anticipation as soon as I cycled the ignition on/ off it gave me a little knock. The shocks are completely new / have run for less than 1k miles. I'll test your exhaust theory next Richard, it seems fairly solid, but I'll perhaps put a rubber piece on the panhard rod to see if that makes it go away. tbh, I hoped someone was going to say that there's a little known widget under the rear seat that taps on the body powered by RL xx and de-programmable in the BECM …. no such luck then

I put a wire tie on a friends tail shaft that only touched the under body off the car when he hit a bump or was under load (really pissed him off )
3 weeks later his mechanic cut it off when servicing the car..... he new who put it their ?
PS someone was saying the other day that the rivets that hold the leading arms on the rear diff (where they attach to the vehicle ) where loose and made a noise at low speeds when going over speed humps exedra, maybe this is worth a look into as well, another part that moves with the suspension.

yep, good point about the rivets, I heard that too, might even deploy some of my green Loctite on them, definitely can't be bothered grinding the heads off and putting bolts in etc That said I'm getting no noises at any kind of speed/ over speed bumps etc, so I don't think this is it.
The centre section of my exhaust doesn't have a hanger on it (blame the PO,, or it may just have rusted off), and although the exhaust looks very solid then I guess it means the whole weight of my exhaust is balanced between the exhaust manifolds, and the four or so hangers on the rear silencer boxes. My exhaust is a bit of a patchwork quilt - might be an excuse to replace the whole thing front to back

Did you try letting the misses out of the boot?

Lol. Or as my missus said, if you want to know who really loves you, lock the wife and dog in the boot for a couple of hours and see which one is pleased to see you when you let them out......

LOL Richard

I have redone the entire exhaust this week - cats/ int/ rear remounted on rubbers etc. Nice and smooth sounding now, but still clunking/ knocking periodically. This should be something electrical as it can do it when stationary. i have disabled the AC so no AC clutch. EAS pump seems normal, and was re-sealed a few months back. Accumulator replaced on ABS recently too. Other than that, what cycles on and off, with some kind of "solid state" solenoid/ valve on the LHS of the vehicle from the odd/ passenger seat area. The sound is like a soft knock of someone's knuckle on abs. Is there anything behind the door cards that would be moving about ?

Behind the door cards? As a matter of fact, you have a very efficient noise generator indeed! A speaker.....Now, this is a stretch, since Range Rover electrics are so solid and reliable, but what if the speaker is thumping....a bit of corrosion somewhere? if a "Low end" stereo, try unplugging the door amp fuse.
If High line, pull all the fuses that run the DSP amp. The issue could just be a bit of random static. I believe the amps are always on in the doors?
Marty?
Both of mine are Dsp, and I have had a few instances where you get a low pitched pop from a speaker when you turn on the key.
Also, the factory sat nav can introduce some interesting sound effects.
Or........ you have an active blend motor, and a sticking door....whirrr-thump.....repeat......

Tnx Bolt, good suggestions. I can remove power from my door amps (High line, but pre DSP) by just turning off my stereo - which I hadn't tried yet, but will do now. Factory sat nav is off, I have pulled out the power plug at the back.
I haven't explored under the LH seat yet, but it also occurred to me that the EAS ECU (possibly the relay) cd be making a sound, and so I could change it out and see what happens

not a broken engine mount , that can make your exhaust knock?

Nope - I'm looking for something that can happen when totally stationary... exhaust and rubbers are all replaced, rear shocks are re-tightened, my next theory is that the exhaust valve for the EAS is somehow transmitting it's noise through the bulkhead. If I lift the bonnet it sounds like the release of air brakes as the EAS pump stops - but i wonder how that sounds from inside the cabin. Do any of the cabin ECUs (esp EAS and WABCO) have any component which could generate a knocking sound, like a relay / solenoid etc?

If your EAS silencer is missing or shot, it has a very loud sound when exhausting.