Exhaust Sound

P

PBV6

New member
Afternoon,

I seem to have lost my depth of sound on my active exhaust when turned on. Down shifts and up shifts are fine, it still crackles and burbles but the depth of sound and general grunt seems to have disappeared.... anyone had any issues like this before?

Regards
Patrick
 
What's happened to the car recently that might explain the change? Just been serviced?
 
Sounds like your loud flappy valves may be stuck slightly closed. They are a PITA to see on the V6.
 
Hello easy to check

just a couple of vacuum lines controlled by an air solenoid valve .. spring return (cant remember which way round) the older models had a separate vacuum pump but this was removed on newer models that take the vacuum straight from the engine.
Also the software was changed on newer models that seem to have muted the pops and bangs when compared to 2013 -2016 models as my 17 plate does not sound as aggressive as others when compared at various car shows. The pops and bangs are all theater of course .. there is code in the ECU that manipulates the oxygen sensor readings with a little bit more fuel when you lift off the accelerator hence all the racket .. basically un burnt fuel going pop .. this was how it was explained to be on the Jaguar tour ... over the years the software has been updated so not so aggressive .. sometimes owners notice this after a service and a topix software campaign upgrade
But as said the flaps are easy to check for correct operation but easier with 2 people
regards
 
It was serviced in Feb but no change back then, happened a few times on the last few drives, doesn't seem to be every time..... I can't seem to find any youtube videos on how to check the exhaust, any advice on how to do this would be great.
 
You don't need ramps - handy with the width of the rear tyres!

Position yourself at the rear of the car just inboard of the wheel and feel along the back of the exhaust with your hand - preferably not when it's hot!

You can feel the small yoghurt pot size vacuum canister and the actuating rod sticking out from it - 1 each side.

Gently push it in against the spring return pressure to check that it is operating correctly - you may feel it is not smooth or squeaks a little on return if it is in need of attention.

A spray of copper grease and a dozen actuations by hand to get it working smoothly again is what I used to ensure it is moving freely for some time.

Having said all that the best preventative maintenance is the Dynamic switch each time you drive :D
 
Hi Lunar, I am not at all sure my active exhaust is working and saw your post. I have located the 2 'yogurt pots' before the exhaust, which have what looks like a vacuum hose attachment coming out of them - that's all I can see. Do I need to disconnect these small hoses to get at the actuating rod? I didn't want to just pull these off. Thanks in advance. Michael
 
Hi Michael, no need to disconnect the lines, just spray the copper grease on the rod which is sticking out then by hand push the metal rod in/out a few times to work the grease in
 
IMG_2454.jpg

Thanks dbv6s, sorry to be a pain. Just had another look...is it the rod that comes out the back of the pot as per this photo?
 
Hi dbv6s, I've posted a picture in my other reply. I'm finding it hard to see what's to move and what isn't as nothing seems to move on either one of the active exhaust housings when I try to free it. I don't want to just spray the wrong thing. (amateur mechanic!) Is this the right place to spray the copper grease - i.e. at the back of the housing that is hard to see and get at?
 
What's the white thing wedged under that rod? Is that stopping it from moving? Maybe that's why it's not working?
 
Thats just the camera flash on the paintwork and the driveway below. Nothing wedged. Am I in the right place for the grease? Is that bar going into the housing whats meant to move up and down. It all looks a bit rusty to me!
 
Hi Michael, did you get it to work and was it stuck as you thought?
I think I have the same problem. I also get a buzzing at low revs from the rear.
What copper grease spray did you use?
Many thanks.
 
sorry for slow reply! As Lunar said you were in the right place - that metal rod should push in and out, pivots on the top of the picture
copper grease all around the area then work the rod in and out to move the grease around

this was a temp fix for me, ended up having to take the exhaust off (cat back), separate the pipes and get inside to the butterfly valves themselves which fixed long term
 
Thanks for that. Is there any visual reference anywhere so I can locate these valves on each side. I’m not sure where to start.
My other concern is the buzzing/rummbling sound at low revs.

Thanks very much.
 
V8 - the valves are pretty much on the end of the tailpipes - stick your head under you cant miss them
V6 - valves are 'hidden' behind the back box and a bit of a pain to get too

on the V6 picture below you can see the metal rod which you need to grease / make sure is moving freely

few pictures below;
Valve / housing which you are looking for;
image.jpg

V6 (behind the back box)
s-l1600 (9).jpg

V8 (on the outer exhaust tips)
s-l1600 (10).jpg

Butterfly valves themselves if you take the pipes off;
Ex1.JPG
 
Update:
I tried putting some copper grease in, but found it difficult to get at and definately couldn't get anything to budge. l left it into the local Jaguar dealership and they have told me it is seized and want £2,500 for a new backbox! That's some money just to geta couple of flaps to open and a bit more noise. Very dissappointed! Next stop is probably an exhaust specialist who hopefully might be able to sort it out. I'm in Bangor, Northern Ireland if anyone in the forum knows of someone locally who might be able to sort this out at a reasonable cost?
 
Hello Michael,

Sorry to hear this. Same thing happened to me. I stumped up & had OEM replacement by Jaguar. My car came with the loud button so I wanted it working correctly. You will find it a very pleasant surprise 👍

Do homework if thinking about aftermarket exhausts or workarounds. Can end up too loud & pi$$ing neighbours off. Many have tried, then removed them, with the associated costs ☹️

Good Luck whatever route you choose.
 
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