Mutley Posted November 12, 2011 Share Posted November 12, 2011 As the title says....Viscous fan is it needed? Only ask as my '95 300tdi has had it removed (before i acquired it) I have had no problems with engine over heating summer or winter, but as it had one on at the start of it's life, I was wandering if it would be best to get one put back on? Are there pros and cons to having them fitted? And if having one on is better how much of a job is it to fit? Cheers Mutley Quote Link to comment Share on other sites More sharing options...
PS_Bond Posted November 12, 2011 Share Posted November 12, 2011 Viscous fans are a lovely idea in theory - automagically swiitching on when the temperature gets hot enough. In practice the things usually end up failing though! That said, I've not done anything about mine (put back on earlier this week); a lot of people seem to advocate putting an electric fan in instead. Very, very easy to fit - providing you remember the threads are left-hand. A viscous fan spanner (32mm) is quite handy. Quote Link to comment Share on other sites More sharing options...
Lars L Posted November 12, 2011 Share Posted November 12, 2011 My experience of an electric fan on a 200Tdi is that it comes on only when offroading. Low speed doesn't push any air through the radiator. I have removed the viscous fan on my present 300Tdi, but keep it with me so it can be put back when needed. Quote Link to comment Share on other sites More sharing options...
ThreeSheds Posted November 12, 2011 Share Posted November 12, 2011 Easy to fit, can be difficult to remove. Not all threads are left handed (my old V8 want one way, the current serpentine V8 goes the other): look at the way the fan turns then think that normal running will tighten it against the drag of the blades, and work it out from there. Never been a fan of viscous fans myself, since I usually own older cars they always seem to be knackered by the time I get them. I know that some people swear by them, but I swear at them and find life much easier with electrics... When working properly they are capable of shifting huge amounts of air though. With regards to whether you need one (or any other kind of fan), it depends on too many things for a meaningful answer. How do you drive? Do you tow? is the rest of the cooling system in great nick? are you likely to be hauling a horse-box up an alpine pass? Touring Greece or Africa next summer? Quote Link to comment Share on other sites More sharing options...
mmgemini Posted November 12, 2011 Share Posted November 12, 2011 Don't need the viscous in Africa. My 300Tdi coped well with ambient temperatures of 45Deg C with the Kenlowe correctly fitted using a proper temperature switch. Quote Link to comment Share on other sites More sharing options...
PS_Bond Posted November 12, 2011 Share Posted November 12, 2011 Easy to fit, can be difficult to remove. A friendly tap with a suitable percussive maintenance tool has usually worked well for me (so long as the belt is fitted). Which is where it's kind of useful to know which way the threads go... I thought on the 300TDI they were all left hand? Reinstallation with anti-seize is what I've always gone for. Quote Link to comment Share on other sites More sharing options...
L835 Posted November 12, 2011 Share Posted November 12, 2011 No! 18 months without any fan on my 200tdi 110. Have towed mini diggers all day up hill, etc,Temp only comes up to slightly past the middle of the guage. Bin the fan! Quote Link to comment Share on other sites More sharing options...
finnarne Posted November 12, 2011 Share Posted November 12, 2011 I removed the viscous fan on my 200 tdi disco shortly after I got it in february 2009. Then used the disco to pull a lot of sail dinghys over the mountain from south of Norway to east of Norway, and back home again, I guess it weight 1-1.5 tonne. Then later that summer, I pulled a trailer with the equipment for a weeks scout camp up to the middle of Norway, still without a viscous fan. No problem. During the winter, while "driving" through some unplowed roads, with ~50-90 cm snow in front of the car (managed to get ~300 meters and back in a couple of hours), I noticed a red light at the dashboard. To get the most of power to the winch, I had turned of the fan inside the car, and was running the engine at ~3000 rpm. Then I bought an electrical fan, and thermostat. (This was in 2010). I had some long journeys with trailer in 2010 as well. Without any fan. The fan was mounted an connected before we went to Polen to participate in 31st Pomeranian. Now I have a switch inside where I can choose between 3 modes. Thermostat controlled fan, fan always off or fan always on. Schematics are here: It works for me. As other has said, you only need a fan if you are going slow, but still put a load on your engine. At least on a 200 tdi // Finn-Arne, who is still moderated, and therefor a bit slow on the replies... Quote Link to comment Share on other sites More sharing options...
Retroanaconda Posted November 12, 2011 Share Posted November 12, 2011 To summarise, if yours is working...keep it. It will shift far more air than an electric one can ever do and requires no extra sensors etc. to make it come on and off. If yours is busted, seized either on or off, then it won't be doing you any favours. In this situation taking it off won't do any harm unless you are really working the vehicle hard. My 200Tdi has an electric fan and it only ever comes on when either doing slow-speed off-road work, or when the vehicle is heavily loaded (not often!). If I had no fan and was planning a trip somewhere hot and mountainous, I would be fitting one. Either viscous or electric, it makes no difference, but if I didn't already have the infrastructure in place for an electric fan I'd put a viscous one back on. Quote Link to comment Share on other sites More sharing options...
reb78 Posted November 12, 2011 Share Posted November 12, 2011 A friendly tap with a suitable percussive maintenance tool has usually worked well for me (so long as the belt is fitted). I've also found that doing it when the engine is warm helps as well. I've had a couple of situations in heavy traffic in summer where i think i may have overheated without the fan, so whatever you chose, i think i would definately have one fitted (electric or viscous - as Retroanaconda says). Quote Link to comment Share on other sites More sharing options...
tacr2man Posted November 12, 2011 Share Posted November 12, 2011 300 tdi 130 DC hcpu , viscous only used to lock up when on long climb at 35C+ pulling 2 or 3 tonne , and then only for a short time , If it works leave it , if it is locked up then bin it . Better than lecky fan in every way . JMHO Quote Link to comment Share on other sites More sharing options...
mmgemini Posted November 12, 2011 Share Posted November 12, 2011 Just a very important note for 300Tdi users. Make sure you have a very reliable and easily readable coolant temperature gauge. If possible fit a coolant loss sensor. The waterpump on the 300Tdi is very high on the engine. Any small coolant loss can be naughty. The header tank is lower then the thermostat housing. So take care ..... Quote Link to comment Share on other sites More sharing options...
PS_Bond Posted November 12, 2011 Share Posted November 12, 2011 By coolant loss sensor, I presume you mean something more useful than "hmm, the vents aren't blowing hot any more"? Quote Link to comment Share on other sites More sharing options...
mmgemini Posted November 12, 2011 Share Posted November 12, 2011 I do indeed. Now that "The Little Black Box" is no longer available in the UK, Can you get one now ? There was a long discussion on this on the Difflock forum. Including a wiring diagram that allowed you to use either the Discovery plastic sender or the Range Rover sender to shew you any water drop. Quote Link to comment Share on other sites More sharing options...
PS_Bond Posted November 12, 2011 Share Posted November 12, 2011 A level sensor in the rad would seem to be a possible solution - if there's a Disco sender then I may have it in amongst my excess bits. Quote Link to comment Share on other sites More sharing options...
mmgemini Posted November 12, 2011 Share Posted November 12, 2011 A level sensor in the rad would seem to be a possible solution - if there's a Disco sender then I may have it in amongst my excess bits. NO. In the rad is far too low. The thermostat housing or the top of the head. The Discovery sender is in the header tank. It's actually fitted to the cap. Oh yes. The way it works is the wrong way round. ie. If you connect it to a warning light. The light will stay on all the time, going out when the level drops. That's why you need a magic box. That magic box can't be identified as part of either the Discovey or the Range Rover loom, electrics or electronics. Quote Link to comment Share on other sites More sharing options...
Retroanaconda Posted November 12, 2011 Share Posted November 12, 2011 The easiest way would surely be a simple float switch in the header tank, or some form of sensor (perhaps conductivity based) in the top of the thermostat housing to pick up on a lack of water. Quote Link to comment Share on other sites More sharing options...
RustyNissanPrairie Posted November 12, 2011 Share Posted November 12, 2011 I've not had a fan my 2.5N/A in the last 4 years but it has a steel head, if I was running a aluminium head engine (200/300tdi) then I'd defo have a viscous fan on there just to be on the safe side. Quote Link to comment Share on other sites More sharing options...
Mutley Posted November 12, 2011 Author Share Posted November 12, 2011 Ouch my head hurts!...........So what are we saying guys? Not a big problem if it hasn't got a fan, all good if it has one that works, and if i drive slow and do a fare bit of towing (up hill) get one on (that works)? So i'll keep my eye out on Ebay for viscous fan, fan cowl and all the other bits that i'll need to install and set it up......Least ways if one gets put back on then theory says there shouldnt be an issue as that is how the engine was designed. Quote Link to comment Share on other sites More sharing options...
cackshifter Posted November 12, 2011 Share Posted November 12, 2011 The easiest way would surely be a simple float switch in the header tank, or some form of sensor (perhaps conductivity based) in the top of the thermostat housing to pick up on a lack of water. Yes, but if using the switch in the header you need a circuit to ignore temporary low level and therefore false alarms as it sloshes round, eg off road. There are some published. Nigel Quote Link to comment Share on other sites More sharing options...
Litch Posted November 12, 2011 Share Posted November 12, 2011 If you are willing to take the risk of cooking your engine then don't bother with a fan, it left the factory with one so it should have one otherwise you are taking a risk regardless of what you hear from people who say that they don't need one. If you don't have one then you will have to hope that your gauge is accurate and that you keep your eyes glued to it. Don't forget that you can cook an engine even in sub-zero temperatures (snow blocking the rad etc), I know this because I have done it and I also had a fan fitted at the time!. Easiest option is just to fit a viscous fan & cowel, should be plenty out there judging by all the people that say they have removed theirs! Slightly more involved option is to fit an electric one with temperature controlled switch, there are 'easy fit' ones that use a special zip-clip through the rad core but I personally hate this idea (radiator fins get very fragile with age) and prefer to mount it solidly to the radiator frame. Quote Link to comment Share on other sites More sharing options...
Retroanaconda Posted November 12, 2011 Share Posted November 12, 2011 Yes, but if using the switch in the header you need a circuit to ignore temporary low level and therefore false alarms as it sloshes round, eg off road. There are some published. Nigel A fair point, that solution would require a 'box of tricks' and we all know the general feeling amongst Land Rover owners towards those! Perhaps then the other idea would work better, drill and tap the top of the thermostat housing (which I believe should be 100% full of water whilst the engine is running) and install a water sensor. Perhaps one like the water-in-fuel sensors found in Td5 fuel filters would be suitable? Quote Link to comment Share on other sites More sharing options...
Mutley Posted November 12, 2011 Author Share Posted November 12, 2011 Ok so if i am to fit the fan back on as per original set up what bits/parts do i need, ie. viscous fan (with fins), fan cowl what else? as money is tight will be looking at used but good condition parts and preferably genuine. Quote Link to comment Share on other sites More sharing options...
Mo Murphy Posted November 12, 2011 Share Posted November 12, 2011 You'll need the viscous hub (buy new), the fan blades and the cowl and a couple of M5 nuts to secure the cowl. Job done. HTH Mo Quote Link to comment Share on other sites More sharing options...
mmgemini Posted November 13, 2011 Share Posted November 13, 2011 Wait until you see the usual viscous fan failure. No not the one where it packs up. The one where the blades come off and go through the radiaror. Quote Link to comment Share on other sites More sharing options...
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