940 viscous coupling noise

My fan viscous coupling on my '93 945 GLE turbo (B200FT - 135,000 miles) has become very noisy, swooshing away all the time. Is this a belt problem or do its bearings need attention? Have been made particularly aware by the silence in this department of my "new" '91 30000 mile saloon!
Any thoughts?
Thanks Simon

http://pic7.picturetrail.com/VOL188/...8/23744414.jpg

Simon,
If the coupling is faulty the only option is to change it, it`s a sealed unit.
Both the links below sell them for around £ 65 + Vat

http://www.gsfcarparts.com/

http://www.eurocarparts.com/

You could also remove the existing fan and fit an electic one.

Colin.

[Ian HT]

I agree with Colin. Could be worth trying someone like C P Motors for a second-hand coupling but would that just be risking more trouble?

I fitted an electric fan (I went posh and bought a new Kenlowe but there must be cheaper ways). It was easy to fit and works well. Not actualy noticed the advertised (and logical) improvement in fuel economy, but you do notice the complete absence of that annoying (or reassuring, depending on your point of view) loud whooshing of air that a standard fan makes. It therefore sounds more economical, not moving so much air about needlessly.

Ian.

[Peter Milnes]

Only problem in changing to electric fan is mounting the thermal switch for the fan. On cars with EGR there is a thermally operated vacuum switch. I believe that if it is removed and replaced by a thermal switch that will do the job nicely (I will be trying it soon myself). I obtained a 960 fan unit which comes with twin relay. I will use the thermal switch to energise the lower fan speed and wire an override switch on the dash for the higher speed. Each speed will have a lamp to tell you what is happening. A steady one for low speed and a flashing one for high speed. When fitted I will be able to remove ( I have a D24 TIC diesel) the viscous coupling, fan blades and bearing mount and with a shorter drive belt for the alternator I should be in business.

All the best, Peter

[Ian HT]

Hi Peter,
You may recall from when this subject hascome up before that I had a bit of trouble sealing the Kenlowe thermostatic control, where it fits into the radiator. I did wonder whether you could use one of the Volvo thermostats that fits into one of the radiator hoses - or make up a similar short length of metal pipe threaded for a universal sensor.

I was able to remove the standard viscous coupling and fan - also the shrouding that fits on the radiator around it. Lots of space in front of the 4 cylinder (petrol) engine now, as the Kenlowe is on the front of the radiator. Query: now that I will be towing next year, where would I site a gearbox oil cooler. When fitted as standard I believe they go just in front of the radiator, but my fan is now in the way. Could it go against the inside of the rad, where it would receive warm air or would it be OK in front - no fan driven air just from movement of the car.

On the petrol engine the fanbelt remains standard as the fan pulley is also the water pump.

Let us know how you get on,

Ian.

[Peter Milnes]

If you have an automatic gearbox then there should be no need for an oil cooler as it should be in the radiator. I do not think that there is provision on a manual box for oil cooling. With the normal setup (auto box) there is a small attachment avaiable to adapt a small cooler in series with the normal rad mounted cooler which would comfortably fit in front of the fan as it is only about 8 by 6 inches in size.

I was looking for the thermal switch fitting from a 300 series car which is a short metal tube set into the top hose which mounts the switch on it's side. So far I have had no luck but as my EGR is now redundant I may get away with using the thermal vacuum switch mounting point. On my diesel I can happily get rid of the fan coupling bearing unit as it only acts as a bearing and drive pulley having nothing to do with the water pump. I can then fit a shorter alternator drive belt which should do the trick nicely.

All the best, Peter

Does the kenlowe go on the inside or outside of the rad? My car is a turbo with intercooler in front of the rad (effectively a second rad) so it will have to go on the engine side

Simon

[Ian HT]

Mine is on the outside of the rad - ideal on my non-turbo, non-aircon 940.
I suggest checking Kenlowe's website and giving them a ring. I believe you can specify "push" or "pull" set-ups; so with one that pulls air it could go inside, under the bonnet. They attach with cable-tie ratchet style fittings which are quite efective, but require you to be able to reach both sides of the radiator to push them together firmly.
Ian.