I have just bought an 03 petrol LC4. There is a whine which is present from start-up, whether the car is in neutral, park or reverse. The pitch of the whine rises and drops with the rpm and never goes away. It doesn't seem to change when turning the steering wheel, and there is no difference when the air con is on/off.

I was thinking this might be an idler pulley, but would welcome any ideas. More importantly, is it OK to keep driving it?

Thanks

Any ideas? Anyone?

Would really appreciate any suggestions before I go to a garage and end up spending a fortune.

I dont know what an LC4 is,Im guessing its either a 100 series Landcruiser or a 120 series Prado.
With those annoying whining sounds from the front,I get a can of belt spray and spray the hoses. This will quieten everything down for a few mins and make it easier to diagnose.
You can also spray the pulleys and idler as this will temporarily lubricate a bad bearing or bush and make the noise stop

The next step is to temporarily detach the belts one by one,and when the noise stops,the problem is with one of the pulleys or idler on that belt.
Obviously you cannot remove the timing belt and I suspect you probably have one large belt that does everything .
Its probably ok to keep driving until the noise changes to a lower pitch

Also feel for signs of heat from the pulleys or idler

Thank you, I'll give that a go