oxtobyd
Member Since: 21 Feb 2023
Location: Lincolnshire
Posts: 24
  
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| Guidance please on finding air suspension fault |
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First post as Disco 3 newbie (have had P38 in the past). Hi everyone I'm trying to track down an air suspension fault, and have followed numerous threads online and in this forum, but struggling to tie it down, and looking for any pointers...
Symptom: Start car, compressor kicks in, after about 15-20seconds, throws a Suspension fault on the dash, and more often than not none of the corners will raise if it tell it to, but sometimes they do somewhat randomly (I get the code C1A20-64 pressure increases too slow when filling reservoir).
Background: So, I got the D3 as a project knowing it had some previous work, and a current suspension issue, what I know from the invoices is the D3 has had in 2021:
- New Air Suspension Valve Block
- New Front Cross Link Valve
- New Air Suspension Compressor (having looked it's got the Aerosus label)
(I think the previous owner gave up and sold this on, after throwing so much money at it)
Diagnostics:
my diagnostics so far to try and pin-point the problem....
- when it decides to raise itself which it does a little randomly, but not often, and I pull the fuses to stop the self-levelling to see if any obvious air-leeks, then it'll sit at correct ride-height for over 48hrs no problems, so that tells me, none of the air-bags have leaks.
- have looked over, listened, and sprayed soapy water over the air reservoir and can't see any leeks (but not dropped it to check the top of it yet, but can't hear anything). Also when I monitor it's air pressure, I see it rises quickly to about 850-900Pa, holds that for around 5-10seconds while the compressor is running, and then it'll just drop all the way back down to about 85Pa (when the compressor stops running at the same time), as if it's getting rid of all the air for some reason, maybe by design, not sure.
- have checked the air intake filter (in the boot) and that looks fine
- I can't belive it's air dryer clogged (after less than 2 years and very little use since being installed by the previous owners garage), but i've ordered a new decandescant kit just in case, but it's pushing air into the reserviour quickly (if the readings are correct), so not sure that's the issue.
- I can see the compressor temp rises from about 45 - 55C when activated, which seems about what i'd expect, so not overheating, and not shutting off because to hot
- I can see the reserviour value opens to 100% when the compressor is running, and then closes when the reserviour seems to empty itself, not sure if this relevant, but thought i'd mention it.
I'm now stumped as to what to look for in the live data to help me narrow this down, my guess is it maybe something faulty with the reservoir, but if it's not a leak, what else would it be? or it maybe the rear cross-over block is stuck, but not sure how to test if that's the case before I start rebuilding it.
any help or pointers for what next greatly appreciated... thanks everyone
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 21st Feb 2023 2:31 pm |
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