Hello to All the Jag Fans!,
Hope somebody can help, as this is hard to explain; please bear with me!
My 99 XJR is has been making a low humming/airplane noise for sometime now. Although the name is mud now, it sounds like one of Bill Cosby's sound effects when they put an airplane engine in Fat Albert's car. It sounds a lot like when you are in a propeller-powered airplane, with that low running hum, the deep bass, you can almost feel it.
When going 40-45 mph, every once in a while the noise goes away for 5-10 seconds, then comes back
It almost feels like the car is being 'held back', like one of the belts was over-tightened? Is that even possible?
My mechanic had to change the belts and per Jaguar updates, he had to change a few parts to accommodate the double-sided belt. I hear it more inside the car, barely hear it outside the car.
As I am repairing the bodywork and fixing a few things, I finally decided to ask the COMMUNITY for some insight!

 

Can anybody answer?
My fear is that if I go to the Dealership they will find other things wrong and try to take another $4000!

 

Might help if you post to the right section of the forum

 

I did, 209 views, no reply hence why I reposted in what I thought was the broader community.
Got your attention mate!
If you first don't succeed.....

 

Gotcha.

I'm not personally familiar with the SC 4.0 engine a few thoughts...

Check the valiance panels beneath the car. Ensure they are properly attached.

If you can remove the SC belt and start the car. See if the noise persists. If it goes away then I would get the SC belt changed.

Could possibly be a bad pulley as well. Check the tensioner as well. You should see the arrow in between the limit lines. If it's near either limit line edge it will need attention. Ideally the pointer should reside in between those lines.

Hope this helps. Wish I had more to offer.