Hopefully I can help..
What year / engine do you have?
Where exactly/location if possible do you hear the noise coming from?
Does if effect the performance of the car etc or any other warning light appear since or prior to the fault?
What its recent service and repair history?
I bought the car a couple of months ago, it is 2006. Very hard to pinpoint any location for the noise, it is just an overall whining sound. I had this once before with my previous car and then it just never happened again. There is no warning light or anything to indicate a problem, but it is very unnerving. This noise happened in this car once before and then disappeared.. yesterday I stopped the car for a while and then started it again, keeping it at 100 or below and there was no noise.
Hi..there thanks for your reply..
Ok..There maybe a few things but as you'll know yourself without actually knowing it actual location or a general location then it maybe a little hard to say really what you would need to check..As with most intermittent faults its really a case of waiting till it happens again and then investigate if possible - it could be a simple as a electrical solenoid/component on the engine or engine bay playing up loose connection to it or loose/split air intake system pipe work or vacuum system line leaks / something on the heater box heater fan / maybe something on the engine on the belt/the belt itself maybe intermittently causing this noise every so often if from the timing side/timing cover then it would be in best interest to have that seen to asap or maybe if it does this or changes pitch when the clutch is used then again could be a part of clutch assembly "release bearing" or if heard through in certain gears again could internal troubles with the gearbox..givin all that it is little hard to say really without knowing the full picture as to where the noisy is coming from to give a better idea what it is..the alternative would be to upload a video on youtube when it occurs and come back here or better still if the car was bought very recently have them just go over the areas as above might be the best solution..I do hope this helps further..