I have looked at other posts concerning this and would like to clarify a couple of points.

I can hear a roaring sound that increases with engine speed. It lasts a few seconds and dies down. I'm guessing this is the viscous fan? It happens from cold sometimes which confuses me though. Why would this be? It happens regularly; is thus normal?

I cannot see any form of electric fan in there.

The electric fan is in front of the radiator/condenser/cooler pack, you can see it by looking through the grille.

I've seen pics of the later viscous fans with wiring going to them, so i don;t know if these have some sort of electric over ride on the viscous clutch.

Definitely no electric fan in front of the radiator. I had the front grille out a while back and had a good look. Nothing within the engine bay apart from the viscous unit, unless the fan is sandwiched between the condenser and radiator which is unlikely.

I'll have a look for viscous wiring.

4.4TDV8 MY2012.

The viscous fan is not electrical. Works on a thermal friction principle as far as I can deduce. The hotter the engine is the faster the fan will be forced to spin. The one in my disco and old tdv8 used to run while cold. Then loosen off and come back in as the engine worked harder. There is nothing that can't be fixed with a hammer😜😜
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Mine comes on on cold startups for few seconds then goes off until stationary on a very hot day with aircon and seats on max, stops when moving forwards and airflow increases.

viscous fans from cold start will roar. As they are acting like they are locked, or directly revving with engine speed etc. then it warms up, either by revving or more likely the first minute at above idle tick over, and then releases, (somewhat)and binds slightly, thus still spinning but like its 'slipping the clutch' -then, when you rev it, it has little sound, and hence no (discernible) roar. Should the engine become quite hot, it will start to roar slightly again, as engine takes more of the roaring air through radiator, and it cools again. all this is perfectly normal.. the reason they act like this is to save drag, and mpg, and create less noise. (when warm) and cut down on fan revs.

indeed you can start the engine when warm holding the fan in your gloved hand, or better still, hold it with a rolled newspaper . to hear any small noise you may suspect. and let it go, and it will spin up etc. do not, obviously try to stop it again whilst running.

symptoms of a faulty fan, are constant roaring, meaning the fan could over rev, and throw a blade etc. or not binding, and causing car to potentially overheat.

in front of the condenser, behind the grill, are normally two electric fans, controlled by the air con, to push extra air through, in stationary traffic to chill condenser, and therefor the occupants.

Many thanks. It sounds as described, but I guess they haven't fitted electric fans to the 4.4 TD?

northernmonkeyjones wrote:

The viscous fan is not electrical. Works on a thermal friction principle as far as I can deduce. The hotter the engine is the faster the fan will be forced to spin. The one in my disco and old tdv8 used to run while cold. Then loosen off and come back in as the engine worked harder.

Resurrection of an old thread....

Did they remove electric air con fan on the 4.4 TDV8?

My air con if fab whilst the car is moving but not so great at standstill.
Been re gassed but was not leaking.

A fan to cool the condenser at standstill would make sense and probably resolve the issue but if there isn't one we are now looking at a compressor change - do they get weak over time or just fail completely?

Or could it just be the clutch? 2016 (L405) Autobiography in Black with Ivory - for ULEZ
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@ Zirconblue

they are not viscous fans, they are cooling fans that go in front of the radiator/condenser

@ stoutgoose

definitely fitted to the TDV8 3.6, very surprised if you don't have one on the 4.4? .
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The fan on the Petrol variant (certainly the AJv8) is controlled thermally and also with an electronic lock up clutch.



My viscous fan is audible from cold for about 15-30 seconds, I assume this is some sort of test cycle. The only other time I've really noticed it is in France a few weeks ago in 37C heat. 

Reading throught this as I have an issue with the AC not working when still in traffic.

Mine is a 2011 4.4 TDV8 and there is no electric fan in front of the condensor or rad pack.

Can anyone enlighten me on if the Viscous fan is used on the 4.4tdv8 for cooling the ac condensor? Trying to work out where to start. As soon as I am above 45mph we get cold air?

Any help appreciated. Current
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