First off, thanks to all for such a great forum. This is my first post. Just bought a 2003 Disco II Se with 75k on it. Had three range rovers before with the 4.6 inside so am pretty used to the sound of the V8. But this disco has a whine that is loudest at idle and increases at higher rpm but is drowned out by the engine at that point. It does it while stationary or moving and continues long after the vacuum-cleaner like sound of the secondary air unit shuts off. Any ideas what it could be? Wasn't the fan near the fusebaox beneath the dash. Can't hear it at all when I stick my head under the hood - only while sitting inside the car. Does it with the air/heater on or off. Is independant of the interior a/c fan. Does not sound like an idler pulley as I put my ear up to the belt and hear nothing (serpentine belt and pulleys were changed at 45k). The overall condition of the car is as new - looks like a 2009 out of the showroom (assuming they kept making them). Does not sound like the wooshing others have reported from an air bubble in the coolant (I have bled the cooling system - noise didn't go away). Ideas???

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Is your Disco equipped with ACE? You can tell easily by looking at the power steering fluid reservoir. Does it have two caps or one?
If it does have two, then I would have to say the noise is probably coming from the ACE pump and is pretty normal, provided there are no leaks.

 

I have to agree with tacomatech

 

My 2003 Disco doesn't have ACE and I have checked the top area of the engine for vacuum leaks and found none. Weird thing is the car runs exceptionally well except for a slightly rough idle (I will be cleaning the IAC unit today). Has anyone had both a Range Rover with a 4.6 and a Disco II with a 4.6? Are there "extra" whining noises to deal with on a Disco without ACE? Like I said earlier, my 3 Range Rovers with 4.6s did not have this particular whine - it is much more pronounced inside the cab than under the hood.

Thanks again for all the help.

 

If you put it in neutral and then rev the engine does it do it? Or do you have to be in gear?

 

At your mileage, you are probably looking at a belt and I would also suggest you replace the belt tensioner as well as the 2 idler pulleys, all of which were know to become noisey then fail.

 

The whine starts immediately when in "park" and in gear - will see what it does in neutral today. re: the belt and pulleys - they were replaced at 45k - two years ago. Can they go out again this soon? I had a RR 4.6 with 112k on it where the belt had not been changed for 60k and I did not hear this sound. The whine is nothing catastrophic btw, just irritating and I can live with it as long as it is not a signal something needs attentiion or is about to fail.

 

Update: I narrowed it down somewhat the whining noise is evident only at idel. If I give it some gas (even slightly) the whining noise goes away. It does it in park, neutral, forward and reverse. Ideas?

 

Check the transmission fluid level.
You might want to have the fluid and filter changed.

 

Look at the belt for cracks and tension, also listen to the alternator, a/c compressor and steering pump for bearing failure.
Are you sur the tensoner and idler pullies were replaced?