My first thought was "heater hose." An easy way to check is to see if it is hot when the engine is warmed up.

 

Yesterday, I had this to say:

I'm going to follow up after over an hour driving today. The car sounds so much better with only the exhaust than with the "enhancement." It's not as loud in the cabin, but there was always something I thought a little odd about the sound. Initially, I didn't know about the system so thought it was just way the exhaust sounded. Once I heard about the system, I started wondering. The wrongness of the sound is gone and I'll never enable it again as long as I own it.

 

No, it's not a water hose! Gaudin shows it as a C2P6376 Resonator and it does come from the intake system via a manifold and hose(s) on passenger side of engine.
And I thought it was a backfire enhancer!!!
Never knew we had one; Gaudin also shows it fits 5.0L '11-12 XJ's !!!
Must be someone who knows purpose of this system...........
Interesting; I'll ask Dr Gregory my Canadian friend..................

 

Please see this thread:
https://www.jaguarforums.com/forum/xk-xkr-x150-33/equivalent-5-0-inlet-symposer-4-2-variants-101271/

 

When I first drove an XK, I thought that there was a hole in the firewall. This inlet noise just seems odd to me. We have the same device in Europe in several compact cars for the masses : plain silly.
And I don't even want to talk about artificial noise through the loudspeakers : even my 12 years old son fond it ridiculous when we recently tried a Peugeot with this gadget turned on.

 

More driving today (regular commute) and it's confirmed. I'm much happier with it disabled.

 

I wonder how hard this task would be on an XFR I bet the cowling needs to come off to get to the hose.

 

At first I thought it might be a Holmholz Resonator used to tune the intake system ala Ferrari but that needs to be before the air filter............Ferrari 360 gains 20 hp at WOT!
It is so much easier to play radio/cd! And therefore not worth disabling the simple 4.2L system IMHO. Interesting topic................

Cheers, Adrian

 

Not sure about the system on the 4.2, but value is in the ear of the beholder. I wish I'd don't this as soon as I got the car. It's probably not worth removal for me, but disabling it was quite simple. Then again, if I'm in there for some reason perhaps I'll unclutter a bit. I'm waiting to see what another on the F-Type forum finds out about the blanking plate for the engine. He's got a V8 though, and said the effort was *not* worth it.

 

Although I assume I have this in my 2012 XKR I don't know what I am listening for. When driving in city mode (non DSC) the car seems pretty quiet and suits my ear and because the top is down if there is any extra cabin noise I guess it's out of my hearing range. When I hit it or turn on the DSC the engine roar is great and something I enjoy. My bride laughs every time I hit the go peddle. So I guess I am a hot and cold noise guy. I must admit I hear a lot of new 5.0L mustangs around here and as they drive around town they are loud which I couldn't put up with for my fun cruiser. Just my 2 cents

 

The 5.0 Jaguar XKR has several of those Helmholtz resonators just like the Ferrari, and an active exhaust.

I like the net effect of the symposer- its name gives it a bad rap, however its no different than an older car where plenty of the engine noises would leak in. Several cars use it- here is Porsche doing the same. Faking It: Engine-Sound Enhancement Explained - Tech Dept. - Car and Driver

What I dont understand is some of the forum guys saying they have had to disable it hear the difference? You can hear the difference by turning the sport mode on and off. its essentially a switch. Or am I getting it wrong?

 

Not switchable for me. Even in "quiet" mode I'd get that in-cabin resonance under load when I hit a certain RPM.

Helmholz resonators on the intake are everywhere. I think anything that uses a MAF sensor will have them to avoid inaccurate airflow measurement from standing waves in the intake. I haven't checked my F-Type, but would be surprised if I didn't find any.

 

Yes the Ftype was forced to make a mistake. (a plastic surgery gone wrong) In an effort to become younger they made the sound gnarly and dirty- but the damn thing makes the noise all the time, even during declaration. It does not know how to prowl quietly. It was the biggest complaint Jeremy Clarkson had during the review. The whole point of a Jaguar is Grace until requested otherwise.

Trade your exhaust for one from an XKR- there are plenty of silly folks out there who would pay you to take your noise problem. Seriously, the Ftype does not need that noise- the XK might, it needs to call attention to itself. Heck I would be blushing if I passed a cop 20 miles over the speed limit with that thing farting.

 

It's not the exhaust that does the noise on the F-Type although it adds to the effect, it's programmed to do the crackles etc in the ECU tune.

 

Makes sense, sorta like a controlled backfire. Has anyone managed to defeat it. Its the one thing that put me right off it.

 

The sound symposer doesn't have anything to do with the crackles and pops

 

Aftermarket Ford Focus symposer block off plate does NOT fit.

So, looks like I will be making a one-off piece for mine.

 

You should trace the part you make and scan it so someone else could make it! Wish you were doing a 4.2.

 

Based on the part you pulled off the manifold the plate should be pretty easy. As mentioned just trace that end and cut it out of a piece of 1/4" aluminum. Maybe 1/8" will do and then get some gasket material and cut that out. You could probably do it with a hack saw or a cutoff wheel. If not take a sketch to a machine shop and they can make one up. Please show us the final version. Oh you might want to ask if anyone else wants a plate . If you go to a machine shop they can make maybe 5 units at the same time without a big cost impact.

 

That was my thinking. It looks like a small plate will do, and 1/8" should be more than adequate. Might not even need a gasket, either. Some anaerobic sealant (can't remember the name of the stuff I've got but I'll check the garage later) should do.

I miss having access to a machine shop. It'd be easy to do a rough version, but milled edges would look nicer.