W124 Viscous fan clutch fitting

[grober]

Thanks for your responses. All sorted now, and the new fan does come on with quite a whoosh.

@kth286, re the workshop test for the fan. The noise test makes perfect sense, and it was the noise of the fan kicking in that I kept expecting to happen when the car temp was risining in traffic, but never heard. The other tests were really to sanity check what I already suspected.

The actual process of changing the fan wasn't too bad. I opted to take the belt off first, mainly for fear of turning the ancillaies the wrong way and potentially dmaaging anything. In the end I managed to improvise using a strap type oil filter wrench to hold the fan pulley while loosening the hex nut holding the fan clutch in place.

The only annoyance was that having been promosed a sachs clutch from GSF when ordering, a brand I'd never heard of, "Flusser" arrived, and that point is was too late to find an alternative as I needed the car. Given more time I would have ordered an oem BEHR unit either form the dealer or elsewhere. This always seems to happen with GSF. Either the part doesn't fit, or it's not the make that was promised.

I also changed the thermostat, which having got the old one out and tested it was fine, so at least I have a spare if needed in the future. Strangely the oem BEHR thermostat was marked as 83c and the replacement as 88c.

In both cases the BEHR units looked and felt much much better made, so for anyone else doing the same jobs, I'd seriously recommend spending a little more and getting the oem brand.

BEHR are good but its seems to be difficult to source their parts in the UK RADIATORS AND COUPLINGS