for about a month and a half ive been getting intermittent air fault lights on the dash. no noticeable issues with stance / ride quality etc etc. she is not a daily driver and is garage kept, so for days at a time she isn't used , and I never noticed any corners drooping. could be the next key cycle and the warning is gone. is there any obvious place to check connection? any suggestions on cleaning the connectors / what to use? I really don't want to go down the wormhole of replacing. I already have a heavy duty suspension job on deck including replacement of almost every component due to bushing and ball joint deterioration.
thanks

 

Possibly a tired compressor. I had that on my 2004 Super V8, basically the warning light comes on if the compressor fails to inflate the system in a given time. If it takes, say a minute longer, then the light comes on. It happens more in the colder weather .
Mine was happening for some months, eventually I had the system checked and the dealer confirmed it was the compressor slowing down.
I found a pattern compressor online and they fitted it, all sorted !!

 

I ordered an aftermarket unit for about $190. looks to be plug and play except for transferring the brackets from the oem. I was on the fence about getting a used oem , but for 20 bucks they gave a protection plan for replacement , so it cant be that bad I guess. we will see

 

There is a kit for rebuilding the piston ring in the compressor which is usually what wears out. Bagpiping Andy's kit is available on eBay and reasonably priced. Since you've already ordered a replacement you might want to keep the old one and rebuild it as a spare. I did one recently and it was a fairly easy job. Once rebuilt my error messages due to compressor time out went away.

 

I saw the guy on wheeler dealers rebuild a range rover pump... I thought about it . I think your idea is good , at least I can take my time and learn about it. do you guys know if the pump swap is pretty straight forward? I don't have the car right now as it is in the shop getting some control arms replaced.

 

Putting a new pump in is easier.
The old one has to come out either way.

 

I have to agree with Wingrider in that it would be easier to just put a new one in. That said the job is not terribly difficult. I had to do it recently and had the pump out in twenty minutes. (just inside the left front wheel well). I actually had a harder time putting it back in as I dropped one of the rubber isolaters and spent twenty minutes searching the engine shield under the car before I found it. Rebuilding it was also straight forward. I did however snap one bolt on the piston cover when I took it apart. Fortunately I work with a group of very talented welders, so one of the guys TIG welded a nut to it and extracted it for me. If you take your time and soak the bolts from underneath they should come out okay. I just got impatient in my case. Once rebuilt my compressor worked fine and as I said cancelled my "suspension fault" message.

On these cars it would be nice to have a spare, especially if your intent is to keep the car long term.

 

Rebuilt old pump twice. Must have been the bleeder valve of something. Seemed to not help. Had small leaks in struts.
Purchased a Miessler brand pump. It definitely pumped more air. As a side bonus it was noisy as hell. Could tell every time it kicked on or off. Pulled three times thinking it was my install.
It died an early death. Quit pumping air, may have shook itself apart.
Bought an Arnott (Wabco) and it pumps air, is quiet as original, and still works great. Cannot hear it from inside of the car.
Dealing with seal rings and a junk pump allowed me to get very good at swapping them. First was a couple hours. It was an hour job the last few times. The grommets and springs that support the pump are a little fiddley. Multiple dropping something and have to let it down, restack, and try again.

 

Found a used one on Flea Bay that looked like new, with low miles, or so they say, for $100.

$100 for a complete Jaguar pump in great shape, shipped to your door is almost reasonable.

Took it apart from the mounting bracket to rebuild, just like taking it off of the car.

The ring was still in good shape, but put the new one in, as i was already there.

The old one is in a bag with the other parts, & another rebuild kit.

With two old Jaguars in the garage, an extra of known wear parts waiting, is a real plus.

 

The problem with just replacing the pump is it's still made badly!
It will wear out too soon as they all do. You need to read Andy's reasoning and why he did what he did. He actually fixes the problem which is a poorly designed piston ring.

Here is his repair kit. Just very well done and a gift to us DIY types!
Air Compressor Repair Kit
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