Grinding noise at Idle.

First time to post here, new Disco owner.  I have always wanted a Disco and finally made the leap - purchasing a 2001 Series II SE7 with 66,000 miles.  The previous owner had a lot of maintenance performed about 5000 miles ago, replacing all wiring, various gaskets, etc. 
 
Now a week into my purchase, I am noticing some things that may need to be looked at.  I tried to search for the problems on the forum, but the answers werent quite tailored to my problem. 
 
1.  During idle I hear and feel a faint grinding noise about every 7-10 seconds.  I can feel it a little in my feet from the floorboard and hear it coming from under the rover.  I first noticed it while sitting in a fast food drive thru about a week ago.  For some reason I want to say that the previous owner had the U-joints replaced, but I dont know for sure.
 
2.  I also have the sloshing problem from the glove box area - but I have read up on that in here and I think I can handle that.  Will someone just tell me specifically where the bleed plug is located - I am not much of a machinehead.  One thing I have noticed is that lately when my Disco starts up the temp gage is sitting all the way at the bottom and doesnt get up to the middle until you get going a little bi.  Is that normal?
 
Thanks in advance.

You can check if your u-joints have been replaced if they have grease fittings. If they dont, your gonna wanna do that ASAP before you blow up your tranny. You may want to crawl under your truck at idle and see if something is rubbing causing the grinding. At a stop and idle it isn't the u-joints. The sloshing problem means you are low on coolant or you have an air pocket. To remove the air pocket, remove the bleeder screw on top of your radiator (once the engine has cooled) and fill the resevoir to the mark.

If your still hearing the sloshing or low on coolant a coolant pressure test is in order. If they havn't been done yet, at your mileage the head gaskets usually fail.

Hey, I'm a new owner also, with no prior experience on these trucks, so I can't speak with any authority on this, but when you say it happens at idle every 7-10secs the first thing that popped into my head was A/C compressor...they do normally load-up every 7-10secs or so. Maybe the bearings are shot? Just an idea.

Thank you.  Like I said I dont know too much about getting under the hood, but I would like to start learing.  I appreciate the help.
 
As far as the grinding goes, it sounds LIKE grinding - but it is not necessarily produced from friction - I dont know what it is. 

Since you're also loosing coolant, you might wanna check the water pump...it's common for water pump bearings to wear out (on many vehicles) and then the coolant leaks out a little weep hole in the underside of the pump housing. If those bearings were bad I imagine they could make the grinding noise you're hearing. Worth checking anyway.

Could it be more of a vibrating noise rather than grinding? Because I have a feint and constant vibration noise at idle that disappears the instant I touch the throttle. It sounds like some kind of body panel resonating. Hopefully some of the veterans on here will chime in with some ideas...

No I dont think vibration is the problem if definitely sounds like something that goes on in or around the engine or axles - it is like the engine hums along for a few seconds and then sounds a little different for a second (but I can also feel it a little) then goes back to normal. 

Just for the heck of it, turn your a/c off and see if it still does it. The noise could be your secondary air pump, if you have secondary air. (emissions thing). Pop the hood and see if you can tell where the noise is coming from..
 
You need to bleed your coolant system and keep you eye on it. If you are leaking , you need to find out where from.
 
On the rear side of your front driveshaft, there is a double cardan joint. It has 2 U-joints in it. See if there are grease fittings on it. If not, replace them soon.

Mine has been doing that RRRRR sound every 7-10 seconds also when idling. I'Ll have to drive by the dealer soon, and will ask what it is. Meanwhile, if you find out, let us know.
 
the bleed screw is located on the inside of the hose that runs accross the top of the radiator.Make sure you wait until the truck is completely cold, and the bottle has to be lifted out of its location, and as high as you can to completely bleed the air out of there.

Thanks everyone.  I really appreciate it.

I am interested in hearing what the dealer says about the RRRR/grinding sound.  It happens on my 2001 Disco when I start it up, but before I put it into gear.  I have no idea what could be causing it!

I had/have a similar grinding sound in my 99 disco II and my mechanic says it's the idle pulley that needs to be replaced. Cheap and easy fix..... could be the same problem?

My pulley is new, so can't be that for me.

Do you see any metal shavings in the oil when you drain it?
 
 Willie

The noise you are hearing is most likely coming from the fan for the secondary air system, pretty common for those who have the emission device on your truck, Look for the fan type device located on the passenger side of the fire wall, that is you problem. Most likely it is normal and not broken, they usually are noisy, some more then others and replacing it won't also make the noise go away.
If you need help with bleeding the coolant system call me. Make sure you only use DexCool coolant when adding to the coolant bottle.

Has anyone confirmed what is the cause of the RRRRR or Grinding sound every 7-10 seconds?  My 2001 disco has been doing it since I got it 2 years ago, but I seems to be doing it more now.  I am concerned that something is about to break...
 
Thanks

Check the idler pulley next to the tensioner pulley. If it is plastic and not steel, then replace it. There is a revised idler pulley(steel) due to a similar kind of sound(bearings in plastic pulley failing due to wear on the pulley drive surface). The pulley is about $50 and takes about 10-15 minutes to replace(with the necessary tools). If it is steel then this is not the cause of your issue.