Still the ongoing issue regarding exhaust drone in my '08 XK. I already had the steel cat converter brackets installed by the dealer that was supposed to be the fix for the drone at 1100-1300 PRM. It did remove the drone at THAT rpm but, unfortunately, it moved it to 1900-2500 RPM range which is exactly where i spend most of my time driving.

Over the weekend I tried to remove the brackets but, did not have the proper extensions to reach up to the bracket mounting bolts on the transmission flange. I called the dealer asking them to remove the bracket and they will but, will charge me for it, probably an hour labor minimum. Quite a fix Jaguar, thank you for making the car worse than what it was.

The new 2000 RPM drone only comes in after about a 25-40 minute freeway cruise, after heat-soaking takes place. Many drivers who do not make longer freeway drives or less sensitive ears (like my wife) might not notice it. I drive 130 miles freeway each way so, for me it is bothersome to listen to the exhaust pulsation for hours.

Here is a QUESTION: does the XK models have only one resonator muffler between the cat converter and the rear muffler? Mine has only one but, when I look at the XKR exhaust diagram I see two. I do not have a picture of the standard XK diagram. Here is the XKR diagram. (Scroll down about half way through the posts to see)

https://www.jaguarforums.com/forum/x...s-50617/page2/

I think Jaguar has an insufficient exhaust on the XKs, if my single resonators is standard. They probably wanted to please those folks who wanted a louder exhaust and basically screwed it up. You should NEVER hear a drone or an exhaust pulsation in a stock car of any kind, even less so in a Jag that supposed to be silky smooth and quiet at cruising. My '05's exhaust was a smoother without a drone.

I am thinking about installing a second resonators, as per the XKR. I have to measure to be sure it fits and hopefully use the same kind as the present one. One reason for wanting the same that some service dept. does not invalidate my 6 year, 100K select edition warranty when they see an obviously aftermarket resonator.

Anyone with an input in this issue? Wonder what a stock resonator would cost at the Jag dealer but, then again, I might be able to find one used from a crashed car.

Albert

 

Albert,
My '07 XK has only one resonator and drones @ 1100-1200 rpm! Easiest solution is to select a lower gear!
What exactly did the dealer attach the extra brackets too? the resonator or the exhaust pipes. You might consider putting one or two long hose clamps around the two pipes, or the resonator, to change the frequencies...........adding a steel (or Al.) bar under the clamps could also change things.
Resonate frequencies are a lot of fun to play with............most modern cars have all kinds of passive weights added ; e.g. my Acura has a weight hanging off the air cleaner intake!
I agree, have Dealer remove the Brackets; low speed is better than cruising speed!

Adrian '07 XK Coupe. '00XK8 Conv, '68 E

 

Thanks Adrian for letting me know that the single resonator seems to be standard on the XK. To answer your question the dealer installed two brackets, each mounted by two bolts into the transmission flange. The top bolt is in a really tight place up high in the tunnel thus, hard to get to. The brackets then graduate into what appears to be aluminum 0.5 inch wide straps that tighten around the top of each catalytic converter.

Thanks for the advice regarding the weights, I actually considered doing it and still might. However, I am very convinced now that the XK does not have sufficient exhaust muffling without that second resonator. As appears from the many posts here regarding that low RPM drone, plus from the fact that the factory issued a TSB, it seems to be common complaint from drivers.

I think that Jaguar listened to the majority of XK drivers who preferred their exhaust louder. My '05 XK (same engine, different exhaust layout) did not have any drone and was quieter with a more sophisticated sound. The '08 sounds like a Mustang V8 that had some not so good after market modifications.

I am looking around for a second resonator. I will not have time for an other few weeks but, I'm pretty sure that I will add either a single two-in, two-out, or two separate inline ones, what ever fits in size in the tunnel. Hopefully then, that Jag is going to purr like a cat at low RPM take offs and growl like and angry cat at high RPMs. Now at 6000 it sounds like a slightly muffled racing engine.

 

Can you tell me the Exhaust Jaguar TSB #, my AllData doesn't show one....................

Thanks,
Adrian

 

Hi,
FYI tried strapping each Cat Converter with a long clamp to the 'diagonal cross member.
It changed the quite BrBr into a louder BOOM because the clamp then transmitted the sound into the whole body! So took them off; much better to just change gear!
I see now why the factory mod. hung the straps from the tranny; which is insulated from the body being hung from engine.
Just having fun so as not to do more Xmas decorations!!
It sure is a great looking piece of engineering from underneath. Have do that more often..........................getting harder to do @77!!

Cheers, Adrian

 

I too have the drone in my 08 XKR at approx 1250 revs. Not that bothered by it, but I wonder whether the "fuse 19" removal might improve it (whilst admittedly also making the car louder...)? Anyone know?

 

Not sure if the drone will go away if you pull the fuse. However, the car may just get loud enough to drone out the original drone :-). Easy to try...

Albert

 

My 08 XKR has a slight resonance at ~1300-1400, but nothing to worry about, especially given some of the loud road surfaces in this city. Now I know not to let the Jag dealer mess with it.

 

Hi


What excactly causes the droning...any guesses?

 

You might want to consider trying to block off the in-cabin resonator...

https://www.jaguarforums.com/forum/x...riants-101271/

I think someone did this where the pipe connects to the bulkhead in the engine bay.

 

Looking at it from a system perspective I think the exhaust pulses hitting the catalytic material causes a vibration / resonance in the pipes. Ideally you could feel or hear it with a screwdriver from below while it's doing it if you could duplicate it on the lift.

 

This is what the TSB says:

Cause: Exhaust Manifold port configuration leading to pressure pulsations, causing exhaust system vibration.