Outer Limits 4x4 Board

This Patrol (youtube*dot*com/watch?v=vhnNYPJOqmc) has a very annoying whistling noise. We have been in it, over it and under it with a stethoscope but cannot track it down. The closet we can get is that it comes from the very front passenger side of the engine down somewhere around the power steering pump. Any help with suggestions or identification would be great.

This noise only comes when the engine is nice and hot. A short 10-15 minute drive from cold is not enough for it to start. You need at least 30 minutes of driving.

The noise comes in at about 1000RPM, but does not change with further increased revs, so this seems to eliminate things like water pump etc.

We have held the fan blades, suspecting the clutch fan, but noise still there and no difference in sound.

Thinking it maybe the p/s pump, we added some conditioner, but this made absolutely no difference.

Thought it may have been the a/c clutch pulley, but after dousing in WD40, there was absolutely no change in the sound.

Tried both belt ease and WD40 on the belts, but no change.

We are really scratching our heads at the moment.

Idler bearings?

Exhaust manifold leak.

Thanks guys, looks like I may have to start taking fan belts off.

The other cold morning, got to work after the usual 30km drive and no whistle, however on the trip home late afternoon, the whistle was there when I reached home.

This is something that is sensitive to temp. Someone suggested the oil pump, but not sure it can make that type of noise.

Have you got a factory locker? Can be from a cracked vacume hose which happened to me, same whisel all rpm only when hot.

Watching your video, it sounds like a vacuum leak to me. Check your brake booster and/or line and fittings, (clutch booster and/or line too if it's a manual).

air intake leak ?

wd 40 on your belts?

He already tried that.

Thanks BadMav, it is a manual hadn't thought of the clutch lines, will check them at the weekend.