i have a viscous fan on a 190 2.5 diesel.

how do i check if it works correctly??
it seams to spin and lots of air is dragged through it when cold and hardly any air is pulled through fan when it is warm

the car gets a lot hotter when going up hill or going over 80 mph on a run so im not sure if fan is working M.rouse@virgin.net

The viscous only comes in above 92 deg C on this model. Should be able to hear difference in noise level at 2000-3000 rpm.