Land Rover vehicles are known for off-road superiority, luxury, and style. Unfortunately, it is not all plain sailing and many Land Rover Discovery 3’s have been plagued by air suspension faults, airbag struts leak, and suspensions dropping to the bump stops, often leaving owners stranded and with high repair bills.
This article covers some of the common air suspension faults and a few short how-to guides which detail how you can carry out your own DIY diagnostics to isolate the leaking air suspension fault. These steps could save you tens of thousands in repair bills later so you might want to continue reading if you own a Land Rover or plan on purchasing one.
The Discovery 3 checks all those boxes and was a major leap forward in the SUV segment for its air suspension delivering a magic carpet-like ride, oodles of space, safety, comfort, and off-road capabilities, winning multiple awards around the globe. Unfortunately, there’s always the big R… Reliability!
INTERESTING READ: Are Land Rovers Reliability Really That Bad?
I had the privilege of owning and Discovery 3 for a while and loved every minute of it. It was the epitome of luxury yet it still felt at home off-road, making light work of whatever obstacle I threw at it. Of all the vehicles I’ve owned, I miss that one the most and my head still turns every time one passes me by.
Enough reminiscing, let’s look at the air suspension problems in more detail…
Discovery 3 Air Suspension Issues
Many design breakthroughs in technology and engineering often come attached with a caveat. They all, unfortunately, have a weak point no matter how advanced or complete they appear, and the air suspension on the LR3’s is no exception. The whole purpose of the air suspension was to deliver superb ride quality under a variety of conditions. This is achieved most of the time and when it works, it works really well! Unfortunately many customers, after purchasing the vehicle started experiencing some or other suspension fault.
Suspension Faults Can Be Caused By Any Of The Following:
- Seized compressor (Purchase a New Hitachi LR compressor Here, alternatively the updated AMK Compressor here)
- Leaking Struts (Purchase new air suspension spring bags here)
- Faulty front or rear valve block (Purchase an LR3/LR4 OEM valve block here)
- A leak in the air hoses (Purchase LR3/4 Air Line Hose Repair Kit here)
- Software update
- Reservoir valve block (Purchase a Reservoir Valve Block for LR3/4 or RR here)
- Height Sensors (Purchase a set of 4 genuine part height sensors here)
(The reservoir valve block is attached to a bracket on the outside of the left-hand chassis rail. Position of the valve block is between the reservoir and the air supply unit. The valve block is located within the air supply unit acoustic box to protect it from dirt ingress and damage from stones)
LR3 User Experiences – Air Suspension Issues
“While operating my Land Rover Lr3 at normal highway speed, approximately 55-65 mph, the vehicle suddenly lost all power to the msg:(electronic air suspension). When this happened the vehicle lost all pressure in air system which maintained a safe ride height and stable handling. Once the vehicle lowers itself onto the bump stops it is literally riding on the frame. I followed the direction given by the in-dash warning system and slowed the vehicle to a stop, turned off and restarted the vehicle, and the vehicle regained it’s proper ride height momentarily and again lost pressure to the suspension system. After further research I have learned this is a common occurrence”https://www.carcomplaints.com
Most air suspension faults start with a tiny leak somewhere in the system. This results in the air system constantly losing air pressure causing the compressor to work harder, pumping more regularly to keep the suspension at the set height. If the problem is ignored and allowed to deteriorate, you will begin to notice a gradual sagging of your vehicle’s ride height once the engine is switched off. This usually happens overnight while the vehicle is parked for a few hours.
Below is another example of a real-world complaint from a Land Rover owner.
“I bought a 2006 Lr3 about a year ago from a dealer in south florida. The vehicle only has 39k miles on it and last week the suspension fault indicator came on. I took the truck to the dealer to have a diagnostic and they told me that the suspension compressor is not working. To replace the part is $1200 because the car is no longer under warranty. If the compressor fails, the suspension fails …”https://www.carcomplaints.com
The design of the Land Rover air suspension is amazing, impressive and it delivers on every front, almost. Even when the system never actually breaks, nothing lasts forever and there will come a time when your air suspension components begin to fail due to wear and tear. Because the suspension is controlled by complex electronics, fault finding and diagnosis can become complicated…. Or does it?
- Loud compressor caused by over-compensating for loss of air in the system
- Sagged front or rear suspension in the morning
- Intermittent “Suspension Fault” warning message appears on the dash
- Intermittent “suspension fault normal height only” appears on the dash
- Recalibration of the struts when the vehicle is switched off to maintain the front and rear ride level.
- Every time the engine has started the system takes approximately 30 seconds to recalibrate and refill the struts
- Leaking air sound coming from the wheel (Usually left front)
How To Locate The Air Suspension Leaks
The most common cause for air suspension leaks is the struts. In order to check and make a diagnosis, you will need to switch on the ignition and raise the air suspension first. This will allow you to gain access under the vehicle to have a scratch around. If you do not hear the air compressor pump running, this could be an indication that the air compressor could be faulty or seized.
You would do well to invest in the iCarSoft Diagnostics tool, specifically designed for Land Rovers and Jaguars. This tool allows you to read and clear trouble codes on full systems such as the engine, transmission, ABS and airbag, etc
The following procedure will explain how to search for leaks on the air suspension.
Soap Water Method
- You will need to make up a spray bottle with some soapy water and squirt it all over the air suspension bags/struts and airlines leading into the bags.
- There is a huge rubber boot over the airbags that prevents access so that needs to be removed first.
- Remove the right rear plastic wheel cover and spray the air pressure valve unit as well.
- These tend to pack up occasionally causing the two front bags to collapse.
- Look out for any obvious leaks in the airlines by bubbles caused by the soapy water
Leaks are pretty easy to find with the soap and water method. Sometimes small leaks can be harder to detect since the LR3 and 4 have a self-leveling system. What that means is that once you turn the key off of the vehicle the system will automatically bleed the air system to ensure it is level at all 4 corners.
Example: If the left front strut is leaking the system will let out a bit of air from the right front to keep the nose of the landy level as well as the rear suspension to match it. That is the reason why you will come out to your vehicle in the morning only to find that the suspension has lowered all the way to the rubber bump stops, which will make your job a bit more difficult to isolate the problem.
So in order to properly check which air strut is leaking, we will need to disable the system first.
The physical configuration of the air suspension is a fairly simple design. It consists of 4 air struts that raise and lowers the level of the vehicle, depending on the driver’s selection. A high-output compressor is connected to 4 air pipes which run via 2 pressure valves (front and rear) to the airbags of each wheel. The compressor pumps air into the bags and maintains the desired ride height by compensating for any leaks by constantly filling up the bags. As mentioned before, if the problem is ignored the compressor will eventually wear out and seize.
Discovery LR3 Air Suspension Components
- Front RH air spring damper module
- Front RH height sensor
- Air suspension control module
- Air suspension control switch
- Rear RH height sensor
- Rear RH air spring damper module
- Air supply unit silencer
- Rear LH air spring damper module
- Air intake filter
- Rear valve block
- Rear LH height sensor
- Upper acoustic cover
- Lower acoustic cover
- Air supply unit
- Reservoir valve block
- Air reservoir
- Front LH height sensor
- Front LH air spring damper module
- Front valve block
Range Rover Air Suspension Components
Disabling The Air System
Your starting point here is to locate the correct fuse which governs the air system and remove it. Removing this fuse will disable all calibration through the night and allow you to more accurately pinpoint the faulty component. The reason for this step is because all the valve blocks fail in a closed position, thus trapping air in each section and cannot flow into other sections of the system.
- You need to find the fuse box and remove the lid first.
- Locate the ride height fuse (Fuse no 3 – 5A Fuse) labeled F26E
- Remove the fuse completely (This disables power to the suspension computer and all the block valves so that none can open electrically)
- Next measure the ride height of all 4 wheels by measuring from the center cap to the bottom of the wheel fender
- Document the measurement of each wheel (Make a diagram to help you remember easier)
- NB: Make sure all the vehicles tire pressures are the same to get the most accurate reading of each wheel.
- You will need to let the vehicle sit undisturbed for 24 hours on a level surface
- Next, after 24 hours return and re-measure the ride height of all 4 wheels again
- The wheel that has lost the most significant amount of air – bingo! That is most likely your faulty strut.
Another reason your front or rear suspension sags to the ground overnight is due to a faulty air pressure valve block. The front valve block is attached to the right-hand end of the front bumper. The rear valve block is located on the forward face of the left-hand suspension turret.
Scenario #2 (Both Front Struts Are Lowered To The Ground)
- This could mean the front or rear valve block is faulty
- The front valve block can be accessed by removing the right rear fender lining from behind the rear right wheel arch.
- It is protected with a plastic fender cover that is easily removed by removing the plastic clips
- Peel the panel back
- Inside there is where the air pressure control valve is located. (This electronic device controls air pressure from the compressor to the air struts, front, and rear
- These valves are prone to malfunction and develop air leaks internally.
- They cause pressure to be lost to both front or both rear airbags at the same time
Land Rover recalled it in an attempt to rectify the problem but unfortunately, many owners ignored it. Check your service book to see if the recall has been carried out on your specific vehicle.
The vehicle must be plugged into a diagnostics machine to identify where exactly the problem is. The diagnostics might identify the compressor to be faulty and kick out a message like “recommend compressor replacement with updated compressor”. The original factory compressor had a design flaw or was a bit too small to service such a huge system and tended to work harder with longer cycles resulting in premature failure. The upgraded compressor is of bigger capacity and a lot more robust.
Land Rover LR3 and LR4 Air to Coil conversion kits
The Land Rover Discovery 3, 4, and Range Rover air suspensions are notorious for failures which could result in huge repair costs as well as a major inconvenience. You, however, have the option of retaining the luxury and class of the Land Rover brand but increase its reliability and add peace of mind with the air-to-coil suspension upgrade kit.
You can purchase the complete air-to-coil kit with the EAS flash tool and complete instructions here.
The solution could be one of three things.
- Seized compressor (you can purchase a new Hitachi LR compressor here) alternatively, the updated AMK Compressor here
- Leaking Airbags (Purchase new air suspension spring bags here)
- Faulty front or rear valve block/cross-link valve (Purchase an LR3/LR4 OEM valve block here)
- A leak in the air hoses (Purchase LR3/4 Air Line Hose Repair Kit here)
- LR3/4/RR Reservoir valve block (Purchase a Reservoir Valve Block for LR3/4 or RR here)
- Suspension Struts (purchase front air struts here)
- Software update required
- Faulty Height Sensors (Purchase a set of 4 genuine part height sensors here)
The Land Rover air suspension is an amazing piece of engineering that defies all laws of physics both on and off-road. If you suspect or detect a fault early enough you can do a DIY fix if you are a hands-on kind of person and continue to enjoy many years of reliable service from your Landy.
Self-diagnosing the problem could save you thousands and most air suspension repairs do not require highly sophisticated equipment. Don’t ignore the problem since it can have a knock-on effect resulting in a massive increase in repair bills.
Happy 4 Wheeling and remember, Safety First!!!