Highway_Star Posted January 3, 2010 Share Posted January 3, 2010 This cold snap brought with it the evidence that my 3.9 Range Rover isn't warming up properly. The real clue was the ice forming on the inside of the windows the other day. So, I did a bit of investigating, two problems. 1. The thermostat had failed open, easily replaced and it's made a hell of a difference, engine warms up much faster and gauge now sits around a 1/3. It never got out of the white section before. 2. (And this is where the collective knowledge of the forum comes in) I think the viscous coupling on the cololing fan is no longer viscous. Am I right in thinking with everything cold (was -8ºC when I tried), the blades should turn with some resistance relative to the hub? I can get them to turn in one direction with a struggle (and I'm 15 stone and not exactly what you'd describe as week), in the other direction the pulley starts to slip on the belt. My thinking is that the fan is whirring when it really shouldn't be. So, being a tight clefted Scotsman, I've formulated a plan (and once again here's where the forum expertise comes in). I have Air Con on the car which I don't use. The AC Condensor which is parrallel to the radiator has two electric fans. They are controlled by a relay in the drivers footwell. I reckon, and correct me if I'm talking parabolics, I could fit one of those rather attractive looking X-Switches, and have it pull said relay in when required. I'd wire an over ride switch on the dash as part of the job. What does the panel think? Failing that there are some reasonably cheap leccy fans on the bay of E these days. Quote Link to comment Share on other sites More sharing options...
errol209 Posted January 3, 2010 Share Posted January 3, 2010 This cold snap brought with it the evidence that my 3.9 Range Rover isn't warming up properly. The real clue was the ice forming on the inside of the windows the other day. So, I did a bit of investigating, two problems. 1. The thermostat had failed open, easily replaced and it's made a hell of a difference, engine warms up much faster and gauge now sits around a 1/3. It never got out of the white section before. 2. (And this is where the collective knowledge of the forum comes in) I think the viscous coupling on the cololing fan is no longer viscous. Am I right in thinking with everything cold (was -8ºC when I tried), the blades should turn with some resistance relative to the hub? I can get them to turn in one direction with a struggle (and I'm 15 stone and not exactly what you'd describe as week), in the other direction the pulley starts to slip on the belt. My thinking is that the fan is whirring when it really shouldn't be. So, being a tight clefted Scotsman, I've formulated a plan (and once again here's where the forum expertise comes in). I have Air Con on the car which I don't use. The AC Condensor which is parrallel to the radiator has two electric fans. They are controlled by a relay in the drivers footwell. I reckon, and correct me if I'm talking parabolics, I could fit one of those rather attractive looking X-Switches, and have it pull said relay in when required. I'd wire an over ride switch on the dash as part of the job. What does the panel think? Failing that there are some reasonably cheap leccy fans on the bay of E these days. The fan should get more viscous (stiffer, sorry for the use of non-family friendly wordage mods, I had no choice) as the water temperature rises - at minus numbers if should be as loose as an MPs grasp of the expenses rules! I don't know my way round a rangie, but I'd guess the AC fans probably won't cope with a hard tow on a hot day (sorry, what? He's in Scotland?) you 'll be OK Quote Link to comment Share on other sites More sharing options...
hattymender Posted January 3, 2010 Share Posted January 3, 2010 For many a moon I ran with a Mondeo fan(£5 from scrappies) manually controlled with a switch & relay. Fan was 'scientifically' attached to radiator with a couple of brackets and a lot of tie wraps. Only issue I noted was cruising in hot weather, it ran a little hot due to fan shroud covering about half radiator. Lot more room to play under bonnet when standard fan and shrouding removed. Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted January 3, 2010 Share Posted January 3, 2010 The AC fans are for cooling the AC condensor, not the engine. Quote Link to comment Share on other sites More sharing options...
Highway_Star Posted January 3, 2010 Author Share Posted January 3, 2010 So I am confirmed in my suspicion that the VC is now more coupling than viscous. In the bin with it then. FF Kinda what I thought, but... I could always remove the condensor as I don't use the AC anyway, there's no belt on the pump I had a scientic set up on my old 82 In Vogue, controlling the AC fans when the engine driven one disintegrated (fan cowl was damaged, and there was contact tixt cowl and blades). A length of wire from the battery to the fans. Towing a dead 90 30 odd miles on a really hot day it was fine. Quote Link to comment Share on other sites More sharing options...
Night Train Posted January 3, 2010 Share Posted January 3, 2010 It would be better to get a proper radiator fan and cowling form a scrappers and fit a thermostat to switch it in and off. The cowling is important as it helps improve the efficiency of the fan by pulling the air more effectively and from a larger area of the rad. Find one from a similar sized rad or find two that will cover the same area. Needless to say, dump the viscous fan if you fit an electric one. Here's another more complicated solution. Remove the electric pulley from the air con compressor that you don't use and modify it to fit on the water pump spindle and fan blades. Use a thermostat to switch the electromagnetic clutch in the pulley on and off to spin the fan. Try to make sure that it is only the fan that is switched on and off and the water pump! Quote Link to comment Share on other sites More sharing options...
Highway_Star Posted January 3, 2010 Author Share Posted January 3, 2010 Interesting idea! What about finding a fan that fits the existing cowling? That would work surely? Quote Link to comment Share on other sites More sharing options...
reb78 Posted January 3, 2010 Share Posted January 3, 2010 Why not replace the broken viscous unit? Much less hassle (and probably saves you money through saving you time in the long run). They are about £70 new. Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted January 3, 2010 Share Posted January 3, 2010 The cowling is too deep really, plus, how would you mount the fan? I have an RRC like yourself, and have a twin cooling fan setup from a V6 mondeo with aircon, this shifts huge amounts of air and not let me down yet, cos me £20 IIRC and to fit I just had to trim a few bits off the cowling and squeezed it gently (bend and shove) into the slot running along the bottom edge of the rad, and the similar slot at the top. I added one flat bracket to it to hold an edge of the cowling off the fins and job done. A mate of mine even thought is was factory, only tell tale bit was the home made crimps on the connectors and the fact if was about 3" short in the horizontal. Can take some pics if you like Quote Link to comment Share on other sites More sharing options...
mmgemini Posted January 3, 2010 Share Posted January 3, 2010 The Defender and the Discovery that are fitted with air con have two thermo switcheds fitted above the thermostat. They are there so that the air con fan will switch on in very hot weather to help the viscous fan cool the radiator. You can buy the viscous coupling separately from the fan. Yes there's a lot more roon with the viscous fan and cowling removed. One of the benefits of an electric fan. Quote Link to comment Share on other sites More sharing options...
iomlt Posted January 3, 2010 Share Posted January 3, 2010 I think this is a cracking idea.. thought about it myself today as when you fire up the ac by heck then move some air... so they are designed for cooling so why not use them? Yes you could easily get a switch and run it... just gota get the fans closer IMO to the rad or ideally behind and get them running. whats it going to cost you? near nothing. If you notice the temperature going too high then either put the viscous unit back on or buy a "proper" fan to do the job, Has to be worth a shot. Quote Link to comment Share on other sites More sharing options...
Highway_Star Posted February 24, 2010 Author Share Posted February 24, 2010 Well, as it's chuffing freezing round here and has been since I started this thread, I elected to spend as little time sorting this as possible. So, £20 poorer via Ebay I have a complete viscous coupling and fan, which spins fairly freely at cold temperatures and gets progressively less free as things warm up. £10 for the relevant spanner + a tap from a Thor hammer to remove the old one, and it's on. The result is an engine which warms up a lot faster, heat in the cabin and plenty of it plus the rev related whirring noise (evidently that was the fan) has gone, leaving more V8 burble to listen to. Happy days! Quote Link to comment Share on other sites More sharing options...
zardos Posted February 24, 2010 Share Posted February 24, 2010 This cold snap brought with it the evidence that my 3.9 Range Rover isn't warming up properly. The real clue was the ice forming on the inside of the windows the other day. So, I did a bit of investigating, two problems. 1. The thermostat had failed open, easily replaced and it's made a hell of a difference, engine warms up much faster and gauge now sits around a 1/3. It never got out of the white section before. 2. (And this is where the collective knowledge of the forum comes in) I think the viscous coupling on the cololing fan is no longer viscous. Am I right in thinking with everything cold (was -8ºC when I tried), the blades should turn with some resistance relative to the hub? I can get them to turn in one direction with a struggle (and I'm 15 stone and not exactly what you'd describe as week), in the other direction the pulley starts to slip on the belt. My thinking is that the fan is whirring when it really shouldn't be. So, being a tight clefted Scotsman, I've formulated a plan (and once again here's where the forum expertise comes in). I have Air Con on the car which I don't use. The AC Condensor which is parrallel to the radiator has two electric fans. They are controlled by a relay in the drivers footwell. I reckon, and correct me if I'm talking parabolics, I could fit one of those rather attractive looking X-Switches, and have it pull said relay in when required. I'd wire an over ride switch on the dash as part of the job. What does the panel think? Failing that there are some reasonably cheap leccy fans on the bay of E these days. Possibly an even cheaper solution? My 3.9 has water temperature sender in the water output from the block to the rad, this was part of the aircon setup. The temp switch is 100 Degrees C which is ideal to run the fans at (the cut in temp needs to be higher than the normal x-fan solution as that is usually put on the radiator return). So if you have this sensor already then you might just need to do a bit of re-wiring. Quote Link to comment Share on other sites More sharing options...
Highway_Star Posted February 24, 2010 Author Share Posted February 24, 2010 I believe you could be right there, mine has some sort of two pronged sensor/switch tapped into the elbow of the thermostat housing. I'll have a more in depth play under the bunnet when the temperatures are in the >0ºC region, preferably into double figures. My garage is not a pleasant place to be at the moment. Quote Link to comment Share on other sites More sharing options...
zim Posted February 26, 2010 Share Posted February 26, 2010 The air con thermo switch located in the thermostat housing has a standard 22mm x 1.5 thread. I've put a 50091 sender into that (switches on at 88-83/92-87 ). I do however wish to run a cooler engine than you with my radiator in the back and it only being used for offroading. I've got a thermostat in for now which opens at 74c. Here is info about intermotor switches : http://partfinder.smpeurope.com/index.html?p=155&typeid=42&recordset=209&value=42 50100 29 M22 x 1.5 82-68 50101 29 M22 x 1.5 84-79/88-83 50250 29 M22 x 1.5 86-76 50012 29 M22 x 1.5 86-77 50090 29 M22 x 1.5 86-81 50120 29 M22 x 1.5 88-79 50295 29 M22 x 1.5 88-79 50296 29 M22 x 1.5 88-79/110-102 50271 29 M22 x 1.5 88-83 50272 29 M22 x 1.5 88-83 50275 29 M22 x 1.5 88-83 50217 29 M22 x 1.5 88-83/92-87 50091 29 M22 x 1.5 88-83/92-87 50212 29 M22 x 1.5 88-83/92-87 50213 29 M22 x 1.5 88-83/92-87 50216 29 M22 x 1.5 88-83/92-87 50221 29 M22 x 1.5 88-83/92-87 50219 29 M22 x 1.5 88-83/92-97 50240 29 M22 x 1.5 90-80 50110 29 M22 x 1.5 92-82 50111 29 M22 x 1.5 92-82 50112 29 M22 x 1.5 92-82 50113 29 M22 x 1.5 92-82/95-80 50218 29 M22 x 1.5 92-82/97-92 50170 29 M22 x 1.5 92-87 50200 29 M22 x 1.5 92-87 50210 29 M22 x 1.5 92-87 50211 29 M22 x 1.5 92-87 50220 29 M22 x 1.5 92-87 50230 29 M22 x 1.5 92-87 50231 29 M22 x 1.5 92-87 50235 29 M22 x 1.5 92-87 50260 29 M22 x 1.5 92-87 50270 29 M22 x 1.5 92-87 50280 29 M22 x 1.5 92-87 50281 29 M22 x 1.5 92-87 50285 29 M22 x 1.5 92-87 50290 29 M22 x 1.5 92-87 50215 29 M22 x 1.5 92-87/97-92 50011 29 M22 x 1.5 93-88 50102 29 M22 x 1.5 93-88/97-92 50035 29 M22 x 1.5 95-85/102-92 50130 29 M22 x 1.5 95-86 50030 29 M22 x 1.5 95-90 50033 29 M22 x 1.5 95-90 50061 29 M22 x 1.5 95-90 50062 29 M22 x 1.5 95-90 50160 29 M22 x 1.5 95-90 50092 29 M22 x 1.5 95-90/100-95 50174 29 M22 x 1.5 95-90/100-95 50104 29 M22 x 1.5 97-92 50282 29 M22 x 1.5 97-92 50103 29 M22 x 1.5 97-92/101 -96 50214 29 M22 x 1.5 97-92/102-97 50190 29 M22 x 1.5 100-95 50195 29 M22 x 1.5 100-95 50196 29 M22 x 1.5 100-95 50197 29 M22 x 1.5 100-95 50198 29 M22 x 1.5 100-95/110-105 50000 29 M22 x 1.5 103-98 50013 29 M22 x 1.5 103-98 50014 29 M22 x 1.5 103-98 50191 29 M22 x 1.5 120-115 Gordon Quote Link to comment Share on other sites More sharing options...
heath robinson Posted February 27, 2010 Share Posted February 27, 2010 ^^^ if you scroll down that list at a certain speed, it feels just like you've entered the Matrix (all be it a monochrome version, run on a bbc micro, where Neo says, in a Dibnah-like accent "Spanners. We'll need lots of spanners") Quote Link to comment Share on other sites More sharing options...
deRangedRoverDriver Posted March 1, 2010 Share Posted March 1, 2010 My RRC air con failed, so I remve the pump, the radiator and put the doule fan closer to the rad, remove the viscous fan and fitted a two way illuminated swith on the dash....the only times I had to switch the fan on was in the sumnmer time if in slow traffic.... Quote Link to comment Share on other sites More sharing options...
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