time bomb?
 

Hi, my 2003 x5 4.4i has a very high pitched whining noise coming from the engine bay when the key is turned to the 2nd position and I cant seem to find out what it is. Is this serious or will it be ok?, also, when I start the car it has a very loud knocking noise but then goes away and when the engine is running and there is a ticking noise coming from the front of the engine when its idling. I would greatly appreciate anyones help on this, Thanks!!!

First of all how many miles on your X?

I'm assuming the engine is running when you hear the whining noise, it could be the secondary air pump, they a have a tendency to fail, but not a big deal you can still run the engine if that's the case. Does the whining noise go away after a few minutes? The secondary air pump shuts down after several minutes. If the engine is not running when you hear the whining noise then it's some other issue and we'll need additional information from you.

Initially when you start the engine you will here some loud ticking, for couple of seconds, until the oil pump pressurizes the oil system and starts to lubricate the cams. Now the ticking noise should be normal when engine cams and valves open and close, unless the sound is very loud, then it needs to be looked at.

I had a whiney noise that was my aux water pump. I had a lead and kept filling with water for a bit, when I fixed the problem and filled the system with the blue dealer fluid, quiet as can be.

The x has exactly 97,700 miles and I can only hear the whining noise when the enginee is off and the key is turned to the second position (able to turn the headlights on). And The knocking noisse is only when It first starts up but when running there is a profound ticking noise coming from the fron of the engine.
Thanks!!!

I cannot think of a reason for the whining while the engine is off.

As far as the ticking noise, it's normal to hear some ticking, however, if there's excessive or loud ticking check the engine oil level, it sounds like the engine is low on oil (maybe).

Do you replace the oil according to manufacturers recommendations? What type of oil do you use? and which viscosity?

Here's a link with some useful information: Karl Pfleger's FAQ of Commonly Discussed BMW X5 Problems

Sorry this link is crap!!!!!!!!

In Key position 2, the coolant will circulate. That is the high pitch noise you hear.

+1. That is how you bleed the system.

Noisy abs-pump ... ?

Thats a relief, I never thought about the coolent circulation, Thanks!!