Blob
Well-Known Member
- Posts
- 202
- Location
- Maidstone, Kent
As many of you are aware, I have been battling a whole bunch of red herrings and silly issues with my L322 in another couple of threads which I'll link here for completeness. https://www.landyzone.co.uk/land-ro...ult-where-to-start.389750/page-4#post-5650424
What I ended up with was a single fault that had a knock-on effect to several others. I wanted to share this as it may well help someone out and it is at least a zero cost test that you can do if you have the same issue. I will try to explain what's happened now.
For a few weeks I have been getting a suspension fault which will sort of upgrade and downgrade itself between yellow and red which is very annoying whilst driving to have it constantly remind you with a bong sound every few minutes. Usually the car would be fine on the first drive of the day but then go into fault after it had been stopped for a while which made me think it could be heat related on the compressor. It wasn't, but that is the level of thinking that you often need to go to when diagnosing these types of things, (time of day, miles covered, raining, dry, going uphill, downhill, turning left or right etc. etc.). I had found that as long as I didn't attempt to adjust the height (Access Mode or Terrain stuff) it would be fine albeit with the warning on the dash. Any attempt to lower the car would result in the error and I'd managed to narrow it to this on GapIID.
These two things pretty much guaranteed that I had an issue venting the pressure and without going into too much detail on my thoughts of how it works I will simply say that there is some "logic" applied to what happens when the car needs to lower and it wasn't making sense to it.
One of the common problems is the drier unit being clogged and as my car has done a fair few miles it was safe to assume that the desiccant could have failed so I bought a rebuild kit for the drier. When I removed the compressor, I took this picture of it and only now do I see the connection to my issue as it wasn't obvious at all then.
You can see a lot of dust all over the compressor. It's over 13 years old now and has a cover on it so I really didn't see anything to note BUT this dust is silica dust and has actually come from the degraded desiccant in the drier. I rebuilt the drier with new filters and desiccant, cleaned it all and put it back together only for the disheartening realisation that the fault was not fixed.
I don't have any air leaks, the car stays up in the air for days while parked and the compressor can inflate everything in a timely fashion, shuts off when you'd expect it to and gallery pressure is all within spec. If I test the valves using GapIID the car raises and lowers as it should so WHAT ON EARTH IS WRONG?
Well, the main point to note here is the word I used earlier, "Logic"; when testing the valves with the Gap tool, there is no logic applied, it simply opens the valves and the function is performed. The exhaust on the compressor is working and air is venting so again, why is it not right?
I decided to rebuild the exhaust valve on the compressor, perhaps if it is sticking and thinking about how it seems to be a hot fault, it would stand to reason that perhaps it sticks when hot. I did a bit of online research and found a video by a company called 4x4airseals.com who showed a bit about stripping it down and I decided to try that route. When I went to their website, they had a number on there and I called them up to talk about my issue and to place an order.
The guy I spoke to imparted some knowledge and told me that the logic part is that there is around 225PSI (I think he said) in the drier which is required to force the exhaust valve open so if you have any drier leaks you won't get the pressure you need to push the air out quickly through the exhaust and thus the logic part will not see the required drop in gallery pressure to accept that it is working then it throws a fault as per the title of this thread. I was confident that I don't have any leaks and explained why but decided it was still worth checking. We then got on to the subject of the Noise Suppressor/Silencer on the exhaust valve. I was asked if I'd removed it and I told him honestly, I tried when I rebuilt the drier but it started to buckle and I decided to leave it alone. They are imperial I think (BSP probably) and have a very small amount of area to grip on. He proceeds to tell me that they can't be cleaned easily and they are cheap anyway so I could take it out or drill a hole in it as a test. This is where the logic is critical, the exhaust valve only opens for a very short time and in that time it must expel a lot of air, if it can't do that you will have this fault.
17mm 6 sided socket is a bit loose but an adjustable spanner did the job just fine and I spilled silica dust everywhere when I removed the silencer, bashed it out not he bench to get yet more mess out of it and then decided to test the car without it fitted. Word of warning, releasing over 200PSI in the car with the doors shut and no cover or boot carpet and parcel shelf tipped up is LOUD! As I sat there slightly stunned I realise the car was dropping to access height without error. I hurriedly drilled a 4mm hole in the silencer and refitted it. I was told that the new ones come with a hole in them (not sure) but I can tell you that I still can't hear it with all of the covers fitted and remember, this is a silencer not a filter.
Everything is now working as it should. I did text the mobile number I spoke to 4x4Airseals on to let them know and ask for his PayPal details so I can buy him a couple of beers. He could easily have sold me parts but instead gave up his time which he didn't have to do. There are less and less people like this these days and I will definitely be ordering from him and singing his praises. Please check them out if you need any parts, they deserve our support.
I'll get a new silencer for this and fit it at some point but for now I am hopeful that I have resolved this issue. If you are having these problems, try this before you start throwing money at the car, it costs nothing but do cover your ears!
Another symptom that I had and didn't correlate was the car telling me it had detected an obstacle and that I needed to clear it and then result the desired height. What I have found is that this can also be caused by the pressure not venting enough. It was the start of my issue (looking back on it), I think it was venting enough pressure to not see a fault but then because the changeover valve was open for both front and rear the air would swap ends. Usually the front goes down and the back comes up as the front of the car is heavier but in my case it was always the front raising. Again, I realised later that must be because I would of a hard left up hill onto my driveway (always happened in the same place) after I'd selected Access Mode and of course all the weight shifts to the back of the car at this point. The system then uses "Logic" to think that the air pressure is out and the car is lowering but the height sensors are telling it that one end is much higher, therefore it is beached on a rock with the wheels dangling and the driver must now do something to fix the problem.
It's a crazy situation but it can only go on what it "knows".
Hope this helps and as always, anyone who knows more and can elaborate further; please chime in.
Richard
What I ended up with was a single fault that had a knock-on effect to several others. I wanted to share this as it may well help someone out and it is at least a zero cost test that you can do if you have the same issue. I will try to explain what's happened now.
For a few weeks I have been getting a suspension fault which will sort of upgrade and downgrade itself between yellow and red which is very annoying whilst driving to have it constantly remind you with a bong sound every few minutes. Usually the car would be fine on the first drive of the day but then go into fault after it had been stopped for a while which made me think it could be heat related on the compressor. It wasn't, but that is the level of thinking that you often need to go to when diagnosing these types of things, (time of day, miles covered, raining, dry, going uphill, downhill, turning left or right etc. etc.). I had found that as long as I didn't attempt to adjust the height (Access Mode or Terrain stuff) it would be fine albeit with the warning on the dash. Any attempt to lower the car would result in the error and I'd managed to narrow it to this on GapIID.
These two things pretty much guaranteed that I had an issue venting the pressure and without going into too much detail on my thoughts of how it works I will simply say that there is some "logic" applied to what happens when the car needs to lower and it wasn't making sense to it.
One of the common problems is the drier unit being clogged and as my car has done a fair few miles it was safe to assume that the desiccant could have failed so I bought a rebuild kit for the drier. When I removed the compressor, I took this picture of it and only now do I see the connection to my issue as it wasn't obvious at all then.
You can see a lot of dust all over the compressor. It's over 13 years old now and has a cover on it so I really didn't see anything to note BUT this dust is silica dust and has actually come from the degraded desiccant in the drier. I rebuilt the drier with new filters and desiccant, cleaned it all and put it back together only for the disheartening realisation that the fault was not fixed.
I don't have any air leaks, the car stays up in the air for days while parked and the compressor can inflate everything in a timely fashion, shuts off when you'd expect it to and gallery pressure is all within spec. If I test the valves using GapIID the car raises and lowers as it should so WHAT ON EARTH IS WRONG?
Well, the main point to note here is the word I used earlier, "Logic"; when testing the valves with the Gap tool, there is no logic applied, it simply opens the valves and the function is performed. The exhaust on the compressor is working and air is venting so again, why is it not right?
I decided to rebuild the exhaust valve on the compressor, perhaps if it is sticking and thinking about how it seems to be a hot fault, it would stand to reason that perhaps it sticks when hot. I did a bit of online research and found a video by a company called 4x4airseals.com who showed a bit about stripping it down and I decided to try that route. When I went to their website, they had a number on there and I called them up to talk about my issue and to place an order.
The guy I spoke to imparted some knowledge and told me that the logic part is that there is around 225PSI (I think he said) in the drier which is required to force the exhaust valve open so if you have any drier leaks you won't get the pressure you need to push the air out quickly through the exhaust and thus the logic part will not see the required drop in gallery pressure to accept that it is working then it throws a fault as per the title of this thread. I was confident that I don't have any leaks and explained why but decided it was still worth checking. We then got on to the subject of the Noise Suppressor/Silencer on the exhaust valve. I was asked if I'd removed it and I told him honestly, I tried when I rebuilt the drier but it started to buckle and I decided to leave it alone. They are imperial I think (BSP probably) and have a very small amount of area to grip on. He proceeds to tell me that they can't be cleaned easily and they are cheap anyway so I could take it out or drill a hole in it as a test. This is where the logic is critical, the exhaust valve only opens for a very short time and in that time it must expel a lot of air, if it can't do that you will have this fault.
17mm 6 sided socket is a bit loose but an adjustable spanner did the job just fine and I spilled silica dust everywhere when I removed the silencer, bashed it out not he bench to get yet more mess out of it and then decided to test the car without it fitted. Word of warning, releasing over 200PSI in the car with the doors shut and no cover or boot carpet and parcel shelf tipped up is LOUD! As I sat there slightly stunned I realise the car was dropping to access height without error. I hurriedly drilled a 4mm hole in the silencer and refitted it. I was told that the new ones come with a hole in them (not sure) but I can tell you that I still can't hear it with all of the covers fitted and remember, this is a silencer not a filter.
Everything is now working as it should. I did text the mobile number I spoke to 4x4Airseals on to let them know and ask for his PayPal details so I can buy him a couple of beers. He could easily have sold me parts but instead gave up his time which he didn't have to do. There are less and less people like this these days and I will definitely be ordering from him and singing his praises. Please check them out if you need any parts, they deserve our support.
I'll get a new silencer for this and fit it at some point but for now I am hopeful that I have resolved this issue. If you are having these problems, try this before you start throwing money at the car, it costs nothing but do cover your ears!
Another symptom that I had and didn't correlate was the car telling me it had detected an obstacle and that I needed to clear it and then result the desired height. What I have found is that this can also be caused by the pressure not venting enough. It was the start of my issue (looking back on it), I think it was venting enough pressure to not see a fault but then because the changeover valve was open for both front and rear the air would swap ends. Usually the front goes down and the back comes up as the front of the car is heavier but in my case it was always the front raising. Again, I realised later that must be because I would of a hard left up hill onto my driveway (always happened in the same place) after I'd selected Access Mode and of course all the weight shifts to the back of the car at this point. The system then uses "Logic" to think that the air pressure is out and the car is lowering but the height sensors are telling it that one end is much higher, therefore it is beached on a rock with the wheels dangling and the driver must now do something to fix the problem.
It's a crazy situation but it can only go on what it "knows".
Hope this helps and as always, anyone who knows more and can elaborate further; please chime in.
Richard
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