AC Compressor shutter
 

Anyone ever heard this noise? I have isolated it to the ac compressor, it only does this when the ac is off or when the car has just started while the ac is kicking in.

You might check the pulley support bearing. It does not do as much when the clutch is engaged as the shaft bearings do most of the work.

Just a thought. Try removing the belt and grabbing the pulley to check for 'play' in the bearing?

Also check the idler and tensioner pulleys just because.

bob

Its the clutch. You need to get that fixed asap or else it'll come off and the belt will no longer turn. Keep RPMs low and no hard accelerations until you get it fixed. (I was a FEAD engineer for 6 yrs)


I've not worked on a jag compressor but chances are good you can just replace the clutch itself and not have to remove the compressor.

Repair AC Compressor on STR? I would love that.
 

I will take a look at the clutch and pulleys.
I would LOVE it if I could just fix the actual problem instead of replacing whole parts. It seems to make so much more sense to me.
But, pretty much every repair on this car seems to require replacement of a whole part :/
Replacing the AC Compressor on the 4.2l SC engine requires lifting the whole engine off mounts so the bolts will clear a support bar. Pain in the ass.
I have not rolled under there to see what clearance I have to work on just the clutch/pulley, but I am super tempted to just try replacing THAT over the whole pump.
I have replaced the stupid pump twice so far, and now this.
(first replacement was bad from the factory, clutch didn’t work correctly. Second replacement is currently the one we are talking about)
Anyone with experience doing this, your advice would be appreciated.

Climate control unit
 

Another idea that has been floated, was the Climate control module circuit through the compressor. Could a problem with the climate control module, a wiring issue between the module and the compressor coil cause incomplete clutch engagement?
The idea was that module, wiring or ground could result in less than 12v being sent through the coil, resulting in weak clutch engagement, thus causing excessive wear on the clutch.
Anyone ever heard of this?

I experienced a slipping clutch on my '02 due to arcing at the compressor clutch control relay. Pics of the burnt relay are in post #4 here:

https://www.jaguarforums.com/forum/s...2/#post1714573


However, when that happened, the AC performance dropped way off. The coldest temperature I could get from the dash vents was about 50F, not 38F like it should be. The problem was very obvious. Who knows, maybe your car was only putting out 50F air, but that seemed normal to you, I don't know. This is why I keep an inexpensive thermometer in the dash vent at all times. It helps me keep an eye on the AC performance, so I can catch a minor problem before it becomes worse.

For giggles, you can remove that relay and pop off the cover. Look for evidence of arcing inside the cover.

For your noise issue, try loosening the serpentine belt. With the engine off, have a helper hold a breaker bar on the tensioner. With the tension released, crawl underneath and try to wiggle the main body of the compressor pulley, the part where the belt rides. I suspect you will find some play there.

I find it curious that you only get the noise when the AC is off. That sure seems to point to a problem with the clutch assembly wobbling around. I don't think that excessive wear on the clutch face (from low clamping force, for example) would cause this noise. When de-energized, you'd have extra clearance, not less. And in the case of extreme wear, you'd have reduced AC performance (due to slippage when energized), but is that the case?

Update
 

So I ordered a new clutch, pulley (with bearing of course) and coil. Raised the car, took the serpentine belt off the compressor and could not feel any play. Everything seemed normal.
While checking everything out under there, I found the top two water pump bolts were not in place 😳
One bolt was still in the track, being unable to fall out because of a support stopping it. The other was gone. With an inability to feel any play or excessive spin on the compressor (or any pulley actually), I thought for sure this bolt was making the shutter I was hearing. So with great dexterity, scraped knuckles, universal joint, a fourteen year old helper and a few extensions we got the remaining bolt back into place.
We put the serpentine belt back on, reassembled and started the car.
Ran perfectly for about 30 seconds, then the same shutter came back. I crawled back under the running car and observed the compressor pulley rocking in and out visibly when the noise occurred. It seemed pretty obvious it was something wrong with the compressor assembly.

So we shut it off, dug back into the job and ultimately gave up. I just cannot get enough leverage in such a tight space. I couldn’t get the clutch unbolted. Such a tough spot on the supercharged STR.

Removal of the compressor requires lifting that side of the engine, and I just don’t have the workshop or the knowhow to do that. So it’s not like I can just pull it off the engine and rebuild it on the bench.

I will need to cough up the money to get a new compressor installed, and that means a trip to the dealership. Why not have it replaced and under warranty at this point.

Also
 

I did swap the relays and it made no change.

Any semi-competent independent shop can handle the repair, including tipping the engine up. You don't have to pay the big bucks at the dealer.

Epic Win for the Resolution!
 

Success!!! A Win!!!

In-Vehicle Replacement of air conditioner compressor pulley:

1. Remove air intake including filter box and air intake tube. Disconnect MAS, vacuum to driver side valve cover and the sensor on the bottom on the air filter box.
2. Remove relay that powers the air conditioner clutch (relay number eight)
3. Use a wire with two small blades as a jumper between number three and number five connection points on the jumper. This will cause the AC clutch to engage with the pulley. With the engine off the serpentine belt will prevent the AC pulley from moving. As the clutch is engaged against the pulley, it will prevent the clutch/compressor axel from turning. This will allow you to apply torque and remove the bolt holding the clutch.
4. Use a 13mm wrench to remove the pulley nut/lock washer and remove the AC clutch. Be sure to remove the spacers on the AC axle and don’t lose them. Then remove the jumper line in the relay port.
5. Using a serpentine belt removal tool, relieve tension on serpentine belt and remove the serpentine belt from the power steering pump and the AC compressor belt.
6. There is a snap ring holding the pulley onto the AC axle. Spray some brake cleaner into the space where the snap ring is, and even use a shop towel soaked with brake cleaner to clean the area so the snap ring is well visible.
7. Feed a Centech digital inspection camera between the radiator and all the lines to a position where you can see the snap ring on screen. Set the screen on top of the engine in a position where you can see it while working.
8. Using snap ring pliers, watching your inspection camera display, remove the snap ring from the AC axle. I had a helper hold the coolant hose assembly out of the way for the part. (This was quite a pain in the rump, but I got it off)
9. My pulley bearing was shot and had been shaking audibly, so it came off the AC axle pretty easy. I did spray it with liquid wrench and wait for ten minutes. You may have to pry yours off with an appropriately shaped pry tool, and if necessary you can lift the car now, remove the belly pan and access the pulley from below. You will find the pulley will not come out of the space between the AC axle and the car frame because there isn’t room.
10. Chuck the rear wheels, jack up the car (if you haven’t already), put the entire front end on jack stands and remove the jack.
11. Use a small piece of 2”x4” and your jack under the engine. Place the wood between the jack and the front drivers-side corner of the oil pan so as to distribute the load on a well supported area.
12. Place the old AC pulley in a position so you can see how much clearance you need to get it past the AC axle. Using the jack, begin to lift the driver side of the engine a little at a time. You should only have to lift an inch or so to provide clearance to remove the pulley. Go a little at a time, and only as much as you need to. As you are not unbolting the mounts, this is cheating. But it worked for me, I got the pulley off, the new pulley into position and partially seated onto the axle. Then lower the engine and place the jack as a backup to hold the car up.
13. You should be able to get the pulley on partially by hand. Then I used a 2”x3” Board that was about 3’ long to set the pulley. I did this by wedging it between the frame and the pulley (not on the AC axle!) and hammering it into the space, thus pushing the pulley into position. This took some work but after working on it the pulley seated and was in line with the water pump pulley. (Note: The rebuilt pulley worked but was slightly different than the original. Therefore the face of the rebuilt pulley extended about 1/16” past the face of the power steering pulley when I checked alignment with a straight edge. However further investigation found the belt channel in line with the power steering pulley.) Removal and inspection confirmed the bearing in the old pulley was shot.
14. Using the inspection camera (still should be in place) reseat the snap ring. Another pain the the rump! I left the car up because I knew I would drop the snap ring several times before getting it into place. An extending magnet retrieval tool was very helpful here.
15. Use the inspection camera, inspect the snap ring to ensure it is in place.
16. Reinstall the serpentine belt and remove the serpentine belt tool.
17. Place the spacers and the clutch onto the AC axle and get the nut started.
18. Reinstall the jumper into the 3-to-5 relay ports, use a 13mm wrench to tighten the clutch nut.
19. Using a feeler gauge check the clearance between the clutch and the pulley. Make sure it is to spec for your car. After some digging with mixed results, I spaced my clutch at about 0.014” to 0.015” using my go-or-no-go feeler gauges.
20. Reinstall the number 8 relay and reinstall the air intake assembly loosely on top of the engine. Plug in all connections and make sure the car will think all is well. Then test by starting the car with AC off, then with AC on.
21. You might go through the process of removing the air intake assembly, removing the relay, adding the jumper, removing the clutch bolt, removing the jumper, removing the clutch, adjusting the spacer number, reinstalling etc... a few times to get it right. I did, but the pulley was a slightly different overall thickness (maybe 1/16” wider because of a thicker front edge)
22. Reinstall the air intake assembly in the reverse of removal, reinstall the number 8 relay, and test drive. Turning the air all the way down to “LO” and using a simple baking thermometer stuck into the vent grating inside the cab, you should soon get cold air at about 40 degrees

Special thanks to:

Motorcarman: I could not feel the play by hand but I could see it happening if I laid under the car while it was lifted and running. Also, when zoomed in with the inspection camera the play on the pulley bearing was pronounced.


Mega Super Special Thanks with a Gold Star to:

KR98664 whose massively detailed write up of everything about diagnosing AC systems on a STR was SUPER helpful through this whole adventure. Because of his info I understand a WHOLE lot more about the AC system and I know everything is well with my ears and a simple thermometer I bought for $3.

Note:

1. I didn’t correctly install the serpentine belt during the reinstall, and after about 50miles it shredded like hell. (Don’t worry, I knew exactly what happened the instant the battery light came on and I had no power steering. I pulled RIGHT over, popped the hood and called a wrecker. No overheating.) I removed and checked the supercharger belt, it was fine. I spent an hour cleaning out the remnants of the old belt before installing the new, along with the existing supercharger belt. Then I did an inspection. From under the car the new serpentine belt looked odd running on the new AC pulley. So I took it off and found I had installed it off by one rib on the new pulley. It looked perfect from above, but below you could see the belt doing weird stuff under the tension as it ran along the pulley. I was positive my own stupidity had caused the loss of the serpentine belt now, and a week of constant hood popping to check the state of the new belt, all is looking perfect.
2. Creative use of several zip ties and an S hook worked well to hold the coolant hoses out of the way so I could get my arm into the rather small space to reach the AC clutch/pulley area.

Another note: In an earlier post I mentioned finding loose “water pump” bolts. I was mistaken, as I meant to say power steering pump bolts. Thank you for not calling me out on the mistake :)




Lastly, I consider this post resolved with the install of a new AC pulley. So if you hear the sound in the video at the beginning of this thread, and it becomes a rattle/shutter that comes and goes... it may be the pulley. And if your adventurous, with the right advice, the right tools and a little perseverance, you can fix it!

Link to inspection camera:
https://www.harborfreight.com/digita...era-61839.html

https://cimg2.ibsrv.net/gimg/www.jag...7cf815473.jpeg
The light on my inspection camera did well to illuminate the area I was working.
https://cimg1.ibsrv.net/gimg/www.jag...cdb73e3e0.jpeg
My view of the AC compressor axle and snap ring with the inspection camera.
https://cimg0.ibsrv.net/gimg/www.jag...79039d8b4.jpeg
Convenient location for the serpentine belt removal tool while I was working.

Would a motorcycle tiedown strap have worked? I've used them in similar situations.

Congratulations on your repair. Excellent use of the inspection camera, by the way.

Motorcycle Tie down strap
 

I’m sure a motorcycle tie down strap would have worked. However I didn’t have one, and I did have zip ties. Either way as long as it held the hoses up and out of the way without removing them and subsequently having to refill and bleed the complex cooling system... it would have done the job 👍🏻

Jaguar did issue a TSB (the ones that nobody reads) for replacing the clutch on the S-Type.

bob

The big difference here is the pics show how to do it without removing the compressor or even discharging the system. The first step in the TSB is to remove the compressor.

Which method is more difficult? Not much clearance to remove the entire compressor, is there?