Strange clicking/whirring noise from front passenger area
 

Greetings -- I have a 2003 LR Discovery with ~58K miles, and two weeks ago I noticed a semi-quiet clicking/whirring noise that appears to be coming from the front passenger area. I first noticed it a few days after rotating my tires... but I'm thinking that might just be coincidental. The sound only appears when the truck is coasting or braking, and immediately stops when I press on the accelerator. If in neutral and coasting, it still makes the sound. The sound stops once I get below 10mph. Finally, the sound is somewhat speed-dependent, so that the clicking/whirring pace slows down as the vehicle decelerates. In general, my Discovery's been pretty reliable although it did have the head gasket replaced about a year ago.

Any thoughts as to what might be causing this? I'll probably take it to a local shop for repair (oil change and brakes pretty much max me out expertise-wise), but it would be nice to know in advance what the problem might be.

Thanks for your help!
Ed (RedAustinIX)

Check that tire for a nail or a screw imbedded in the tread or lower sidewall. It may have been in the tire for a while but you didn't notice it while the tire was on the back or other side.

I had what was left of a screwdriver stuck in a tire once.... click, click, click as you described.

Have youir front driveshaft inspected, it is fails you will be buying a new transmission.
When u-joints go bad they can make all kinds of weird racket.
Get it looked at MONDAY!! Not Tuesday, not Monday afternoon, Monday morning.
They need to remove it from the truck to inspect it, not just a visual, but a bench test.

Did you manage to solve this problem? I received as a gift a 2000 disco 2 with ACE and I am feeling this humming in driver floor just as you describe. It only has 15,000 miles

As above suspect the front shaft.

if the 15k miles are genuine then it has sat for a long time, so any kind of humming could be multiple things.

but the front drive shaft might be the most expensive to ignore, it’s likely original.. Easy to swap if you have the skills.

after that, brake rotors, bearings that have sat for years etc.

double check t-case oil level

Thank you,

After a week using the Tiger (She's named because she is painted as a tiger camo) I noticed that it doesnt humms anymore outside of 1000-1150 RPM, I'm pretty sure its ACE related.
I'll be sure oil levels are ok and I may purge these fluids.

Front Driveshaft looks OK and doesnt make noises.

If you think it might be another thing please write to me. Thanks

As time passed and I've been using it more than the previous owner, the humming I mentioned before from the ACE unit, has disappeared complete.

Now because it was most of the time stationed, a new issue has appeared. Cylinder 5 is dead. Engine works well and i can ride no problem but engine check light strobes when cyl. 5 doesn't work and at about 50mph steady it starts to wiggle.

What do you think I should do? I was thinking of getting it open and change every cyl. rings and clean it all..

Cylinder rings should not be necessary. Try changing the spark plug and the plug lead on that cylinder.
It is also possible that you have a head gasket leak, but there is too little information here for that to be confirmed.