I noticed on the past couple drives that my 2012 XKR 5.0L is making a different sound under the hood, hard to describe, but maybe a whirring sound. It is almost electric motor spinning sound, most noticeable 2k+ RPM. It happens both in neutral and while driving, so I'm assuming an accessory bearing of some sort. I took it to a specialist yesterday and they thought it was the A/C compressor, which the previous owner just replaced early last year. They were confident that was the cause and I had them perform the replacement. I went to pick up the car today and it is still making the same sound! They are now continuing to investigate.

Here is a clip I took in my garage. Has anyone experienced this sound occurring to their 5.0L? Any ideas?

 

Tensioner pulley? Those go bad sometimes.
Release the pressure on the belt, then spin it with your hand. It should be nearly silent. Also, maybe remove the belt and try to wiggle and spin whatever other pulleys there are.

 

I agree with Cee Jay about testing. This is a supercharged car. That means you have two belts on it. I would pull the SC belt and spin the tensioner and idler pulleys; then spin the SC. Then repeat for the accessory drive pulleys and components.

This shop would see me go full Karen if they just shotgunned a part, returned the car to a customer and the noise was still there. It *could* be that the A/C Compressor was bad and one of multiple sources. It could also be that they guessed and guessed wrong. I'd definitely request the old AC Compressor and have them show me why they thought it was bad. That's a pricey guess to be wrong on.

On BOTH my X100 XKR and X308 XJR, I had the supercharger idler pulley bearing go. I eventually had the SC tensioner pulley go on one, then the serpentine idler on the other. I went screw it at one point and just bought the bearings for both tensioner and both idler pulleys to just be done with it. Was like $40 for the set of 4.

 

curious, does it change with engine temp? when cold and hot?

 

No, I it does not change with engine temperature. No update from the shop at this time.

 

I wouldn't go near that shop again!
Pretty sure the shop test drove the car and noticed the sound is still there and realizing their expensive mistake but thinking/hoping the stupid customer won't hear it when picking up the car!

 

I'm a bit frustrated and venting. Two more days in their hands and this shop appears to be giving up. The shop owner put off calling me until 7:30pm last night and told me he tried another A/C compressor and it still makes the same sound. Of course it did, because that is not the cause. I asked if tried isolating each pulley/accessory and he said he would today. When I called to follow up today at 5:30pm, he claimed he was busy with several people and will call me back in a minute. I gave him 2 hours and at 7:30pm he answered, claimed he's been swamped and still has another person. He said he tried isolating each pulley, but couldn't determine the source.

I asked to see the A/C compressor he took off my car and he said he should still have it and will show me. He claims it sounded like marbles rolling around. I have the records from the previous owner and he replaced it 4k miles ago, last September, so I was very skeptical that it was the cause. He wants me to come in tomorrow in person to discuss. Unfortunately, I had already paid on Wednesday when I thought I was picking up my car repaired.

If anyone has advice, I'd appreciate it. I want my car back, but I don't want to be out almost $1,700 for a job that didn't fix anything. I'm in Virginia and doing some research on what laws may be applicable. I thought I was being proactive, trying to get something fixed before it may become a bigger issue. The car did not make this sound at all until the past 50-100 miles, 2-3 drives. Unfortunately, this specialist that I had a good experience with last December is becoming a nightmare unless he makes things right.

 

Honestly you probably need to work with the shop to hopefully get this resolved for no additional money but unless you’re willing to sue, it’s unlikely you’re getting money back for the idiocy so far. Maybe if you paid with a good credit card they may be able to assist but even then iffy. There’s things you can go to like reviewing negatively but easiest is to move on.

Sorry you’ve had to deal with a crap shop.

 

OR, give up and call it experience and move on to a different repair shop.
OR, diagnose it yourself with basic hand tools and a couple hours.

 

When I need to find a sound in the engine area I use my red neck stethoscope. I have an old vacuum cleaner flexible hose, 3-4' long. Put one end near your ear and point the other end towards the engine. You will find the exact source of the sound quickly and cheaply. Good luck.

 

That’s a two man job..... Somebody’s got to hold your beer. 🙂

 

It's all in the tools...

 

alternator?

 

Update... The owner of the shop asked if I could meet with him the next morning, a Saturday. We met and he spent a couple hours with me showing all the troubleshooting they did and that all signs point to the A/C compressor. He had the car up on the lift and walked me through what they did. He offered me a stethoscope and instructed me on how to test each of the various pulleys. He showed me how the A/C compressor makes a rock tumbler sound and said that the previous compressor was in worse shape, even louder. I heard how all the other pulleys and tensioner were smooth, but then when I put the stethoscope on the A/C compressor, even the brand new one makes the rock tumbler sound. He installed a second replacement compressor and found it to have the same sound as the first replacement.

I appreciated the time he took to meet with me on a Saturday morning and walk me through everything and had a great chat. He wants to have me as a satisfied client and build a relationship for future work and I do as well. We isolated that the sound is coming from the A/C system, because when turned off, the whirring goes away. Unfortunately, after two new compressors, it still makes the sound. He doesn't know what else it could be and I think he is probably just as frustrated as I am. I at least feel assured that it isn't something more critical on the engine that could fail, but I do hope to find a fix sometime.

I came across this older post, but the OP didn't update if they fixed it:
https://www.jaguarforums.com/forum/x...und-ac-131990/

I saw reference to the TSB JTB00207 for an AC whistling noise, but not sure if that would be the cause since mine increases with RPM, when I saw some saw it goes away as the RPM increases. I'm going to continue to dig on the forum for ideas, but if anyone has suggestions, please let me know.

 

Here is the video amcdonal86 shared in the other thread of his car making what seems to be the same sound as mine, but from the outside. I might try to take some other clips of mine when I get time.

 

sounds like this is actually a great shop. i'm glad to hear that.



i don't know exactly the disposition of the compressor as i haven't had occasion to troubleshoot mine, but i do know a bit about sound. did you move the scope away from the compressor body towards the pulley, and away from that towards the bolts/mounts/locating dowels/etc.?

vibration traveling exclusively through a brand new and perfectly fine compressor, tested at said compressor, will be heard from said compressor, even if it's just a wallered-out bolt hole that is the actual source.