e34 viscous fan tapping

[dwaynos]

hi, i know this sound real stupid but i have a 1994 520i and there is a tapping comeing from the viscous fan. it cant be heard with the bonnet down but wen its up u can hear it gettin louder as revs build up. i proberably sound pety but it sounds bloody awfull. to my knowledge it hasnt been doin it long.
what could be wrong?

thanks

[Rus]

Grab a long screwdriver or a piece of hose. Place it around the water pump. Make sure that its the fan assembly and not the pump tapping. Does the noise persist when the clutch engages and the fan goes full speed?

[dwaynos]

so what exactly do you want me to do with the screwdriver or peice of hose?

thanks

[whiskychaser]

so what exactly do you want me to do with the screwdriver or peice of hose?

thanks

Use it as a stethoscope to find the bit the noise is coming from Keep your head and any other parts you want to retain well away from the fan, belts etc

[Rus]

The basic procedure goes something like this:
1) Take hose or screw driver and place one end on a part you suspect makes noise.
2) Place your ear on the other end of your listening device.
3) Listen

Obviously this is for stationary parts and as whiskychaser said, you gotta be careful to not put your head/body parts in harms way. BTW, if you suspect the cooling fan clutch to be the problem, remove the fan assembly from the engine (when it is still cold) and fire it up. If the noise is gone, then you've found your culprit. HTH