Over the last couple of weeks I've started to notice a small change in the sound of my XJ as I'm accelerating through the first couple of gears. The motor sounds louder with a very subtle howling overtone. The best way I can describe the tone is that it resembles that of a city bus as it accelerates from a stop, but MUCH quiter. Had I not been familiar with the usual sound of the car, I wouldn't think anything of it. I can't say that I notice any performance difference. Shift points, acceleration all seem be the same. The only variable I can think of is that the temperature here in Arizona has just started hitting 100 degrees F (38 C). I wouldn't think the ambient temperature would have such an impact, but it doesn't typically produce the same sound in the morning or late night when it's a bit cooler, however there have been some exceptions to that. I searched to see if anyone else has posted this behavior but the closest thing I found was this https://www.jaguarforums.com/forum/s...ht=engine+howl in the X-type forum about issues with the transfer case. I'd love to know if anyone with an XJ has had a similar experience. Again this is very subtle so perhaps I'm just being overly sensitive?

 

I should have mentioned that my XJ8 is a 2006 with 55,000 miles.

 

Could you be experiencing tire roar/noise? The XJs are sensitive to tire noise as the tires ware. See if the noise varies with the type of road surface you are on. Mine raise so much hell on Macadam (asphalt & stone) you can't believe it.

 

I hear exactly the same thing. A sort of whooshing noise at low speed. I think it has something to do with heat. I hear it more after I have been in traffic for 1/2 an hour or more. It has been hot here in Austin in the last few weeks and I am sure they are related. Perhaps the fans running somehow makes the noise? Either way, I haven't noticed any change in performance or any issues so I put it in the "XJ8 model weirdness" category.

- Tim

 

Although I'm running the far from quiet Pirelli PZero's, I'm pretty certain it's not tire noise. I've both heard, and not heard "the howl" driving in or out of my neighborhood so the road surface is not a variable. The sound definitely reacts to the rpm of the engine as opposed the speed of the car.