Blob said:
Well, it's different to mine as your one lives outside the car it doesn't need to be as quiet. I assume you didn't buy a new compressor? If that piece flows air nicely then it should be fine and I expect your other one is too.

Start with the basics. Take that part out of the currently fitted compressor and test it, it will be loud but it if it works fine then your issue is there and it probably needs cleaning out but I don't see value in drilling extra holes in that type of silencer, it won't clog like the brass ones.

I'll keep coming back to the drier unit though, we need to know if that is new or not. Basically your car is telling you it can't vent enough air when it expects to so you either have:
A blocked silencer (unlikely seeing what it looks like)
A clogged drier unit
A non-working exhaust valve - that usually presents a different error although I have no idea on the code but it's in my linked threads.

The Discoveries and RRS can suffer from the compressor bushings failing which you'd have seen when you replaced it I expect but in case you didn't or they aren't that bad yet, it's worth checking the wiring to the exhaust valve as I have seen them chafe on the bracket. It doesn't always rub through the wire but it break down the insulation and then you'll get high resistance and poor connectivity on the exhaust valve which might also cause this problem. If so yo need to cut out that wiring and solder in a replacement section with heatshrink and proper insulation, don't bodge it with crimp connectors or you'll be doing it again next year!

EDIT: Just realised this reply isn't to the OP, is it two of you with the same issue or are you both working on the same car? Most of this still stands of course, just interested to know.
Click to expand...
It's just me think I've posted in two places maybe sorry , I have a new compressor on car this parts off the old one but still seeing same fault , is there anywhere I can get a detailed diagram of the Hitachi compressor, and where does the pipe connected to the exhaust travel too is it to a tank somewhere ? Thanks for help , it's definitely not dryer as all new it's a headache haha thanks though it's appreciated 👍
 
Unlike my car where the compressor is inside, yours is under the car so the silencer is different. The piece in your hand (if I'm correct) has a plastic pipe going into it? Owing to the fact that your compressor could easily get submerged if you were a bit splash happy or wading too deep it has an intake filter in the N/S/R 1/4 and this is also the exhaust muffler, the air that comes out of the compressor is sent back up to it and recycled. If that filter is a bit clogged, I suspect that's where your issue is.

Take the pipe out of the exhaust port (bit in your pic) and then test your suspension. I wouldn't suggest driving like it for water and dirt ingress but it will be ok as a test. If that fixes it then you just need to put a new filter on the car and you're good to go. Doesn't look like you can disconnect it in the boot sadly as those joins look permanent but I have found one seller with a replacement foam element so it may be possible.

PDF attached of the LR filter replacement instructions along with a pic I found on eBay of what you're looking for.
1723659974638.png
 

Attachments

  • AIR SUSPENSION AIR FILTER (G426769) REMOVAL AND INSTALLATION.pdf
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backinblack said:
Thought you may not have noticed the new poster, didn't realise you were responding to something over a year old :)
Click to expand...
Blob said:
Unlike my car where the compressor is inside, yours is under the car so the silencer is different. The piece in your hand (if I'm correct) has a plastic pipe going into it? Owing to the fact that your compressor could easily get submerged if you were a bit splash happy or wading too deep it has an intake filter in the N/S/R 1/4 and this is also the exhaust muffler, the air that comes out of the compressor is sent back up to it and recycled. If that filter is a bit clogged, I suspect that's where your issue is.

Take the pipe out of the exhaust port (bit in your pic) and then test your suspension. I wouldn't suggest driving like it for water and dirt ingress but it will be ok as a test. If that fixes it then you just need to put a new filter on the car and you're good to go. Doesn't look like you can disconnect it in the boot sadly as those joins look permanent but I have found one seller with a replacement foam element so it may be possible.

PDF attached of the LR filter replacement instructions along with a pic I found on eBay of what you're looking for.
View attachment 323823
Click to expand...
Thanks , took the piece out like in my hand and it makes a racket and shut off again , I took the other pipe next to it off and seemed to play the game and fired up ? The pipe in pic is this an exhaust too or where does that go to as seemed to start pumping when I took that one off ?
IMG_20240814_213017.jpg
 
So here's what we have
Suspension shutting off
Then fitted new compressor worked for 5 mins
Back to suspension fault
I removed the pipe in photo from compressor and she fires up ,not so good lift on front end but that maybe the mid block so I'll deal with that later but after removing pipe in pic smaller of two it works fine , can anyone tell me what this pipe is please and where it goes to after compressor it's not the nut one the one above
IMG_20240814_213017.jpg
 
Ok, now seeing it in situ, I was wrong. The top one in your picture appears to be the exhaust as it is connected to the solenoid valve.

What do you mean by "Suspension shutting off"? I get that you're frustrated with this but you really need to be clear on what is happening and what the codes are, we'll help you out but remember we are trying to diagnose this fault from words only so bear with.

The bottom pipe in the picture is the inlet so when you disconnect that it will be loud as the air rushes in.
Top pipe is the exhaust
There should be one at the other end of the drier unit that goes to the air tank.

Next steps, leave the exhaust disconnected, clear the codes and test.
What are the errors (if any generated)

I have other thoughts around the lift too but we'll cover that later.
 
Blob said:
Ok, now seeing it in situ, I was wrong. The top one in your picture appears to be the exhaust as it is connected to the solenoid valve.

What do you mean by "Suspension shutting off"? I get that you're frustrated with this but you really need to be clear on what is happening and what the codes are, we'll help you out but remember we are trying to diagnose this fault from words only so bear with.

The bottom pipe in the picture is the inlet so when you disconnect that it will be loud as the air rushes in.
Top pipe is the exhaust
There should be one at the other end of the drier unit that goes to the air tank.

Next steps, leave the exhaust disconnected, clear the codes and test.
What are the errors (if any generated)

I have other thoughts around the lift too but we'll cover that later.
Click to expand...
Hi I took exhaust and inlet off compressor in site and started her up ,then as soon as I pressed for a raise the car fault sound beeped and lights on suspension went out again and suspension fault flashed up , that's with both pipes off compressor in situe and that's the new compressor too just don't understand it ? Could it be the relay ?
 
I think there's a pressure sensor, so the ECU might turn compressor of if it does not sense any pressure build up ?? Not sure.

Unplug the compressor & try it direct from battery 12V to see if it produces pressure ?
 
What codes are you getting? That will tell you what it perceives to be the issue. "Suspension Fault" on the dash could be a hundred things.
 
Hi have solved the compressor issue all good then only fault in having in left rear height sensor no supply , but I've just replaced it and put a new plug on as was broken and corroded ,I ensure the wires were connected to the correct pin as I took off but still saying the same ? Any help appreciated or wiring diagrams for the back left height sensor would be amazing ,thanks very much for your help Tony 🙂
 
pwood999 said:
yes . . . forum rule. Always post what the fix was.
Click to expand...
Hi yes sorry the compressor I bought was a duff one the new one went in and was perfect working as she should ,I've reconned the Hitachi one I took off but just waiting for parts will keep spare now ,but yes definitely was just compressor being duff ,thanks for the help too !
 
Blob said:
What was the fix for the compressor then?
Click to expand...
A full replacement again but got full refund in duff one they sent first ,just wasn't spinning in the motor properly inside compressor well they said it sounded like the motor was duff ,but out new one on and all brilliant !
 
On another note 😉 does anyone know if the rear height sensor lr023648 is the correct height sensor for my discovery 4 2011 sdv6 GS please as some places say yes and some no as I may have the wrong.kne and that's why it's not working , also if anyone has the plug wiring diagram for this rear left sensor that would be a big help thanks everyone this is the only fault left now !!! At last ,best wishes Tony 🙂
 
Hi

Indeed that’s correct, assume ur getting confused with the RRS that has dynamic suspension , apologises as got confused at first of why ur thread was in the Range Rover section when u have a discovery 4

Have posted over the wiring diagrams etc and what to check over on ur other thread, if there’s no 5Vdc supply voltage to the height sensor can check at the suspension ecu that sits on the drivers side A pillar to ensure the supply Vdc is there first and foremost

The 5vdc supply wire come from the ecu , through that large connector ref C0376-36 C0390-36 , that sits on the near side chassis then onto the rear height sensors , u can also do a continuity test from the ecu to the rear height sensor using a multimeter or using diagnostics via the live data section

If u look on the wiring diagrams it shows u which PIN numbers and what colours go to each height sensors

Linked ur other threads

www.landyzone.co.uk

Rear left height sensor no supply

Hi all just wondering if anyone has the wiring diagrams for rear left height sensor on discovery 4 sdv6 GS 2011 , have changed and new plug but still says no supply wiring all looks fine to looms etc so maybe wired it wrong any diagrams would be brilliant thanks all !
www.landyzone.co.uk www.landyzone.co.uk

www.landyzone.co.uk

Discovery 4 sdv6 GS Dreaded suspension fault showing

Hi If you have a diagnostic tool that supports live values, you should be able to watch the gallery pressure drop (exhaust valve opening) just before the air compressor starts. You can force the air compressor to start by calling for a height change. The exhaust valve vents the gallery pressure...
www.landyzone.co.uk www.landyzone.co.uk

Hope that helps
 
Last edited:
Blob said:
Unlike my car where the compressor is inside, yours is under the car so the silencer is different. The piece in your hand (if I'm correct) has a plastic pipe going into it? Owing to the fact that your compressor could easily get submerged if you were a bit splash happy or wading too deep it has an intake filter in the N/S/R 1/4 and this is also the exhaust muffler, the air that comes out of the compressor is sent back up to it and recycled. If that filter is a bit clogged, I suspect that's where your issue is.

Take the pipe out of the exhaust port (bit in your pic) and then test your suspension. I wouldn't suggest driving like it for water and dirt ingress but it will be ok as a test. If that fixes it then you just need to put a new filter on the car and you're good to go. Doesn't look like you can disconnect it in the boot sadly as those joins look permanent but I have found one seller with a replacement foam element so it may be possible.

PDF attached of the LR filter replacement instructions along with a pic I found on eBay of what you're looking for.
View attachment 323823
Click to expand...

Hi

Am in Kent as well

Plus 1 as when I had to change that filter that sat in the boots 1/4 I cut the pipe and refitted using a pushfit coupling

When I fitted a new compressor the exhaust pipe was very tight so got a longer piece of pipe and done a loop to prevent the pipe from kinking

Also posted some wiring diagrams etc over on the discovery section as got confused at first as wondered if the OP had a RRS seeing it was posted here as well

At least with all the info shared the OP can do a quick continuity test between the ecu and height sensor, followed on with a Vdc test, found the only connector between the x 2 is that large connector that’s sits on the near side rear chassis
 
Blob said:
Ok, now seeing it in situ, I was wrong. The top one in your picture appears to be the exhaust as it is connected to the solenoid valve.

What do you mean by "Suspension shutting off"? I get that you're frustrated with this but you really need to be clear on what is happening and what the codes are, we'll help you out but remember we are trying to diagnose this fault from words only so bear with.

The bottom pipe in the picture is the inlet so when you disconnect that it will be loud as the air rushes in.
Top pipe is the exhaust
There should be one at the other end of the drier unit that goes to the air tank.

Next steps, leave the exhaust disconnected, clear the codes and test.
What are the errors (if any generated)

I have other thoughts around the lift too but we'll cover that later.
Click to expand...
All done no faults all fixed thanks for all your help ! ,do.you or anyone know if these would be ok to use in old compressor ? Just wasn't sure ,thanks and best wishes Tony 🙂
Screenshot_2024-08-31-12-16-50-375.jpg
 
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