After all the great work done by others concerning the defeat and removal of the entire Symposer system. I decided to disable mine. I am so glad I did too! The Symposer puts out a lot of weird and strange noises into the passenger compartment and I always thought it was very out of character for a car such as the XJ. With it defeated I find the car MUCH better to drive without all that silly crap coming from the Symposer!

Turns out it took about 30 minutes to do the entire job. When I pull the blower to port it and replace the snout I plan to remove the entire setup and plug the trumpet attached to the fire wall.

Remove the engine cover and the plastic elbow and clamp are somewhat easy to get too. Now use caution as you will need to lay on the engine to access this and be sure to NOT break any of the engine compartment plastic stuff. I lay heavy pads/towels on top of the engine for protection.



I use and recommend cable clamp pliers to hold the spring clamp open. Pull the rubber hose off.
Here are 7/8" Silicon caps I used. These are used in powder coating and are good to 350+ F.




Don't know if it makes any difference or not but I put a cap on the engine side and a piece of all-thread in the disconnected rubber hose. Stock clamp used on the rubber hose and a small hose clamp was added to hold the silicon blanking cap in place. Not sure it's needed but put something on there anyway.




So it's a bit of a hack until I can fully remove it. Went for a drive and love what I did NOT hear!

I also had to buy 10 of these 7/8" silicon caps and would gladly send one to anyone that wants one.
Send me a PM with your address as I think I can just drop one in an envelope.
First come,first served!
.
.
.

 

@clubairth1 Many Thanks for your post. I think I fully agree with you mentioned motivations to do this trick.

If I understood well, near by the motor, a vacuum tube transfer “energy, vacuum” to the inner part. Here the tromped transfer the vacuum to noise? Correct?



I think, I have to close the motor-vacuum part.

The internal symposer part is the to be activated part. So, no energy, no noise?



The piece of boult is not directly needed?

 

The Symposer is vacuum controlled and I left all that in place for now.
The bolt is probably not needed but it does lead to the open "Trumpet" mounted on the firewall.
I plan to plug that as well but used the bolt temporarily.

Yes the noise is still being generated by the Symposer but can't be heard because of the cap.
.
.
.

 

Clubairth1,

After your mod is made, is there any advantage to removing the remaining Symposer parts?

I remember when I first heard the Symposer in action, I thought the exhaust system was defective. Now I’ve become used to it, but I think I’d still rather do without that unusual sound.

It would be a different story if it sounded like that straight six cylinder split manifold exhaust on the E-Type!

Vince

 

No not really required. I won't even try until the SC is removed.
You could just ignore it from now on too. It's way in the back and I honestly did not even know about it until I read about it on this forum.
Like you I thought that it sounded a bit strange and then read about the Symposer.

But I got to say-Man I wish they put that money towards something of value like Aluminum cooling pipes or maybe some extra Engineering on the water pumps?
Same for the soft close doors. Kinda cool but we have some serious problems that Jaguar should have worked on before all this gingerbread stuff was added in.
.
.
.

 

Clubairth1, to your knowledge, do the 3.0 liter XJs have the Symposer? Like you, I didn't know about these superfluous devices until reading these threads. I've never looked back there to know. I know the 3.0 liter Land Rover Sports have a Symposer. - Just wondering if I have one of those silly contraptions to disable.

 

That is a very good question and I don't know?
OK yes the 6 cylinder has a symposer too as here is a parts listing showing the 2014-2021 3.0L engine using #C2Z30725. Note it does not list the models?
6 cylinder symposer

One thing I could not figure out is that part number does not work for a 2014 XJ with the 6 cylinder according to that web site.
Maybe simpler to just take a look??
It has to be pretty much where my photo's show it even on the 6 cylinder.
.
.
.

 

Thanks, Clubairth1. I looked and where the Symposer is supposed to be, I have a large void. There is also what looks like a punch out on the insulation where the transducer portion would probably mount to the fire wall. So, I don't have a Symposer and that explains why the 3.0 liter XJ isn't shown in the model list for that part.

 

Good to know!
Thanks for reporting back.
.
.
.

 

Interesting. I have a 3.0 liter XJ and it has a symposer.

Vince

 

Interesting...mind posting a pic of it? I don't see it on my 2015 3.0 L.

 

My goodness – you’re right! I don’t have one either. I should have looked before I posted. My bad.

When I bought the car, I couldn’t help but notice that the normally quiet exhaust became considerably louder when the engine was under load. The salesman explained that it was a normal sound for the car because it had a symposer. I accepted what he said without verifying.

Now I’m wondering if what I’m hearing is actually normal for the car or whether the exhaust system is somehow defective.

Sorry for the misinformation.

Vince

 

No problem...I thought I was looking in the wrong spot. My 2015 has a very muted exhaust which lets the supercharger whine shine thru!

 

Thanks for reporting back as I thought all the cars had them until Jaguar dropped it in I think 2022 on the F-Type?
As always with Jaguar it just depends.
.
.
.