My car began making a two stage brief chirp/squeak when turning off the car. The noise is definetly coming from the rear of the car and it's quite loud.

I've tried pushing on the rear of the car to see if it's in the suspension etc but no noise; its from the rear for certain and only occurs directly following switching off the car! I also tried moving the exhaust by pressing on the tips with my shoe and they move as they should but no noise from there either. I've googled this and found one post on this forum which pointed to the active exhaust; other searches always pointed to under the hood but in my car it's seems to be much closer to the underside rear.

I'm thinking it's the valves on the active exhaust as I believe (correct me if I'm wrong) they may operate/close at shut down?

Anyone have this issue or can share some thoughts?


TIA

 

There are numerous problems in the case you have mentioned. First is engine exhaust mounting misaligned, or sticking caliper (if found this, dont be afraid coz it is common) or excess fuel in the system burning off which makes the squeak noise.
so if possible give some other signs for the same. so that we can found the better and exact solution.

 

Thanks. The noise takes place about asecond or two after the car is turned off and it sounds like a metal on metal two stage squeak coming from rear underside of car. I would doubt its a caliper as the car is in park and it actually occurs when foot is either on or off brake pedal. This is a weird one for sure.

I've read that there's a pneumatic valve that controls the active exhaust; wondering if that little item might be the problem?

Curious, if there's any Jag techs on this forum?

 

Dupe...Unable to delete

 

Apparently I'm not the only one with this type of issue...I'd bet in my case it's the ebrake cable or the active exhaust device under the left rear wheel well as mentioned in the thread below; just wish I was still able to crawl under a car like I used to.

https://www.jaguarforums.com/forum/x...ed-help-61362/

 

I was going to ask if you could reproduce it by messing with the parking brake...

 

Thanks. I did try turning the car off with ebrake both on and off yesterday but it made no difference. I will try to see if i can pull fuse 19 to see if that stops this dreadful squeal.

 

Jaguar Forum.co.uk • View topic - xkr exhaust squeak

 

Perhaps the exhaust is grating against something as it cools down? Could it be an exhaust mount?

 

I don't think it's a cool down thing as it only happens about a second after shut down, sounds like a two small squeaky door hinges one after the other.

 

Man, little things like that drive me CRAZY. I feel for you.

Does it happen if the car is parked nose up or nose down on a steep hill? If it is an exhaust to body rub it might not manifest if the car is loaded or unloaded in the rear, worth a shot. Better still, ideally you'd put it on a lift and then shut her off, see if it does it then (and maybe easier to localize). But that's a pita, of course.

I've been fooled by the true location of sounds before. Sometimes chirps can travel down parts of the frame and originate elsewhere. I'd get a friend to help, at least it sounds like it does it all the time, which should make things easier. Silly as they look, mechanic stethoscopes work pretty well at directionally locating where noises really come from and aren't expensive.

As to your theory about the active exhaust, why would the active exhaust actuate going from idle (in regular, non 'dyno' mode) to ignition off? My understanding was that the valves are normally in default (non loud) position, and only open/actuate under the right conditions. Can't see why they'd decide to move open to 'loud' mode when you shut the car off, but I'm no expert. But absent knowledge that this is the case it doesn't seem intuitive that it'd articulate open when you shut the car off, only to have to close again when you start the car (in 'normal' mode).

Chirp there even if you just start the car and shut if off ten seconds later, when everything is still cold and you haven't moved the car even an inch? That'd rule out a bunch of exhaust expansion/heat issues, though can't see how those would manifest when you shut the car off. Hm.

Does our magnetic suspension drop a little when the car is shut off? Might be something there if it does, as the car settling down could introduce opportunities for metal/metal contact in any number of places. If our cars do drop when shut down, that'd be my prime suspect as to potential cause.

Just trying to be creative, btw, no tech expertise here

Skeeter

 

Thanks Skeeter.

I think when the car turns off the valves may open back up to allow that throaty sound at start up; my car at cold start sounds great. Yes a lift would be great and no doubt the dealership will sort it out providing it makes noise for them.

Yes, squeaks and rattles make me crazy to and I'm usually very good at finding them both inside and out. Man, if was my old self I'd be crawling under under there on my back until I found that little bugger...

I dont think our cars drop down a bit, my E55 with pneumatic suspension used to. Curious, do we have any Jag techs that post here?