Hi all,

In the past few days a squeal has developed when I accelerate and turn. When I am cruising at a speed (any speed), there is no noise, but if I touch the accelerator at all the squeal pops up. It is varying levels of loud, and stops after a second or two. The harder I push the pedal the less squeal happens (in general)

I am thinking a belt is slipping? Thoughts on where to start? Easy to fix and work in I hope

2011 XK converible 75k miles

Thanks all!

 

Assuming that you have a significant other, park your XK and open the hood. Stand by the front of your car while the other person starts the car and puts the transmission in neutral. See if you hear squealing noises as the other person varies the engine speed and steering wheel angle. If so, try to pinpoint where the noise is coming from. Good Luck!

If you're unsuccessful, the next squealing noises will be coming from your wallet!

 

Mmm. Just tried this, there is no squeal at all. It seems to only make noise when it is moving which makes pinning down a location a bit hard, although if I were a betting man I would say left side, possibly rear.

Any thoughts or ideas? It does sound "rotational" could it be a bearing or something?

Stuck brake pad? It doesn't happen only after taking my foot off the brake though

 

One other bit of information that may or may not matter.

If I am correct that it is coming from the left rear, that wheel was taken off about 2 weeks ago to fix a hole in the tire. I forgot to check the tightness of the lugnuts, could this be related? I will loosen and re-tighten to the appropriate 92#ft tomorrow. It is possible that I haven't noticed the noise in between then or now, or possibly something warped after being under tension longer?

I am spitballing here

 

Definitely retorque that wheel, particularly if the technician was not a Jaguar specialist who knows the proper spec. I know this from experience.

When I bought new tires for my XJ at Discount Tire, a large national chain, I asked the salesman what torque spec they use. He told me to wait a second while he looked it up on his computer (proprietary Discount Tire device) and showed me that it was 110 ft.lbs. I told him that was incorrect and it should be 92 ft.lbs. I also asked him to make sure that his technician used the socket wrench in my trunk and hand tools, and not the impact wrench, to put the wheels back on so as to not damage the 2-piece lug nuts. When I got home I retorqued all the nuts to make sure they weren't buggered and were properly tightened.

 

I also used discount tire, and I am willing to bet my bottom dollar they used the impact wrench (primarily because I didn't tell them any different.) Hm. Will have to adjust for the future. What is the lugnut size? 19mm? Tha KS in advance!

 

Could be brake shroud coming loose or heat shield from under neath the car , ps don't over tighten your nuts could be painfull lol

 

So I woke up early this mor nng to play with my (lug)nuts, and the sound still persists!

It seems to get worse the longer I drive, it isn't there when start off. Although it is less today to be fair. I tried to record the sound, I have attached a recording, it isn't the best because i am moving, BUT you can hear it a few times throughout. The clearest might be the first 5 seconds of the clip, you hear the engine then a new sound. Some of the sharpness ( high pitched?) Of the sound is lost, but hell, here is hoping you guys have some ideas.
Some more information, the tires are very near the end of life (2-4/32). It doesn't sound like squealing tires, but hell, will try anything

George, how can I tell if the shroud is loose?

Apparently the sound file is the wrong format, will get tech support (dear wife) on it and post that soon

Edit: tech support is amazing. Please hear attached

 

19mm is the correct wrench size, not 3/4 inch.

Tire jockeys who work for busy chain stores are always in a hurry. They'll grab a 3/4 inch socket because it's what they often use, stick it on the impact wrench, and the wheel is off in seconds. It'll do the job, but it'll also bugger the outer shell of the lug nut because it's too big - it's 19.05 mm - just enough to wobble on the nut and damage the corners of the soft outer shell, which will enable it to spin around the solid inner nut and make it difficult to remove. If that happens, try hammering your 19mm socket back on and pray it works. This won't happen until you get a flat on a dark, rainy night in the middle of nowhere.

I bought two 19mm sockets from Harbor Freight to keep in my XKR and XJ. They're deep with a rubber coated exterior, made specifically for lug nuts. Why take a chance that your tire jockey doesn't have one?

Take good care of your nuts so you can get them off without any problems!

 

This audio may be better. Taken with the roof up and driver's window down

Again, very easy driving with light throttle movements, you can hear it in the beginning

 

So I did some more driving and testing today. The squeal only happens from 1500-1750 RPMs, and only if I am light on the accelerator. If I am "pushing through" that range, no doubt as all. But cruisinng and touching the accelerator causes the squeal almost always. Or lightly accelerating through a subdivision for example.

But never on deceleration, unless I am turning hard. ... Any thoughts? I am thinking belt and tensioner maybe??



Maybe this will help narrow down some ideas! Thanks!!

 

Some more observations

In park or neutral, getting to and maintaining 1500 RPMs no squeal

I set cruise control to maintain 1500rpms, and went for a drive. Whenever the engine had to work (flat ground to maintain, and uphill) the squeal was present. Whenever it didn't have to work (coasting flat and downhill) there was no squeal. And with the speed constand, the squeal was there as long as the engine was working to maintain speed.

I would really appreciate any thoughts and ideas!

 

I just got a shiver run up my back.....
Have you checked the wheel bearings on all four wheels? A lateral force at low speed COULD start scraping a bad wheel bearing.
To be honest, I haven't listened to your video yet.

 

I haven't checked, but if I am in drive with a foot on the brake I can make the sound so I am not sure the bearing makes sense thankfully

 

Still can't hear it , But using the iPad at the moment will try again on the pic tonite , the brake shrouds are behind the discs and if coming loose might rub on the discs or are a rattling noise , you would have to get under the car give them a pull see if any movement , If so it is an easy job to tighten a lot of guys remove them

 

What like are your brake pads ? They move about and cause squealing

 

Jack up the car and grab each wheel at 3 and 9 o’clock positions and manually push and pull back and forth to look or feel for any play. Also put a bar under each wheel and pull up look for any play.

look at ever suspension part- tie rods, ball joints, hub to spindle. Something is loose and you should be able to see or feel it. Might take two people. One to do the pushing and the other looking. I use my hand across a joint to feel for small movements between parts. You can usually feel a loose bearing or balljoint easier than seeing it

 

Take it to a garage get a mechanic to come on a test drive hopefully it will replicate

 

Update:

I went to my uncle's house today to get some help with this issue. We took it for a drive, he said he has never heard a sound quite like that before (He used to own his own engine shop for years). He said it was coming from the rear and that it sounded like a heat shield or something loose maybe? We brought the car back and started tapping on the exhaust box to try and find what might be causing it and we found that if you hit the middle front of the exhaust box with a rubber mallet, you can get the sound to happen (much quieter obviously, but you can hear the weird metal vibration sound). Sooooooooo we are thinking I need to replace the exhaust box. He said it is definitely not a mechanical issue, and that a weird combo of flow/resonance, and something wearing out is producing this sound in such a weird way.

I have attached a couple of audio clips, you can definitely hear the metal squealing/squeaking when I hit the exhaust box. As a note, I can only get it to make the sound when it is warm. after about 25 minutes of cooling, I cant make the sound any more. Any other thoughts before I start looking for a new exhaust box? Is this a reasonable and rational approach/place to start? Thanks!

 

Good find! Loose baffles in the muffler!