My 1998 convertable ac compressor may need changing. Any one done this? Do you have to go in from underneath (I have the workshop manual but it's not clear on this point). Do you need to put oil into the compressor before you fit it or can this be added when it's regassed?

 

I have, and I went in from underneath. One member managed from above by removing lots of stuff:
https://www.jaguarforums.com/forum/x...7/#post2203235

Disconnecting the metal pipe from the bottom of the PS pump will make it easier to remove the compressor, but you'll need the correct crowsfoot spanner which I didn't have.

It's the two connections to the back of the compressor that are the killers. They're a real PITA to get to, even with a RHD car:

Note the new leak I created. If you remove the little black clip that retains the transmission fluid cooler lines against the engine block, you will be able to flex them somewhat which will help when you're removing the compressor

If you get a new Denso compressor (part # 471-1358), it will come pre-charged with 120ml of the correct PAG oil. The installation instructions (copy attached) give guidance on how much oil to retain, although I found this article more helpful:
https://carfromjapan.com/article/car...-to-ac-system/

Note that Denso requires the receiver/dryer to be replaced at the same time for the warranty to be valid.

I bought mine from Rockauto (I have no affiliation) in the US as, even with shipping, it was less than half the price I could find over here. I know shipping has gone stupid since covid, but just checked and it's showing at $265 & about $65 shipping.

Forum member Gus has a how-to on his website here which will give you guidance:
JagRepair.com - Jaguar Repair Information Resource

N.B. Most of the suppliers show the wrong part number for MY98-on 4L motors (er - Denso included). 471-1358 is correct, 471-1382 has an extra connection for the compressor lock sensor which is only for the MY97.

You may also need to stock up on expletives

 

MichaelH, thanks for your post, it's full of useful info.

 

I changed the compressor on my 2003 XKR last year. I know you are going to think that I'm crazy, but I do preventative replacement of parts. My car has 91,000 miles on it, and it's 21 years old. The parts don't last forever. I have three theories here:So, when I was in changing the compressor, I also changed the condenser. I have the car's records, but no indication that it had ever been changed. Not knowing exactly what happened to the compressor, it's probably a good idea to change it. Of course, change the drier, and flush the lines.
I had to pull the radiator to get the condenser out. Radiator is supposed to be good for 150k miles, but I didn't know if the coolant had been replaced regularly and.or if the radiator might have been clogged a bit. It was fairly cheap, so I got a new one of those. New coolant as well, of course.
All of the hoses are 21 years old. I had a tiny leak, which really was just a coolant smell, but I bought all of the hoses, coolant tank, thermostat. I've changed all the hoses up front so far, but still need to do the valley hoses. Smell is gone, but some of those hoses are 21 years old, so I'll replace them soon.
What the hell, as long as I'm in there, new alternator. Of course, new belts, tensioner pulley bearings and idler pulley bearings, yada yada yada.

If you just change the compressor, that's fine, but the following week/month/whatever when you have to replace the alternator, radiator, or whatever, you have to repeat a lot of the same work. Since you know which end of the screwdriver to hold, you are saving a FORTUNE over having someone else do the work. (I saw a dealer invoice for $700 to change spark plugs, including $29 each for the plugs, the identical plugs you can get at AutoZone for $6. I bought the better $9 plugs from RockAuto).

I bought most of the parts from RockAuto. Some of the hoses came from other places, wherever I could find them. All in, it was probably around $1100-$1200 in parts. Take it to a Jaguar specialist since the dealer doesn't work on old cars? Yeah, wait a couple months, and the bill probably would have had two commas in it.

Good luck.