nicks90 Posted November 15, 2011 Share Posted November 15, 2011 i like my viscous fan. yes they can fail, but so can electric motors powering the fan / multiple wiring connections / relays etc when regularly dunked in muddy water and getting covered in lovely UK road salt viscous fan doesnt care about getting wet or muddy, it just works. when your rad is half blocked with mud, the viscous can pull soooooo much air flow through it that you still wont overheat. The nominal amount of air flow you get when the engine temp is under control - eg low speed offroad and low speed towing - means your intercooler keeps good airflow over it. Might not sound important, but when you are labouring up a bloody big hill with 2.5t hanging off the back end screaming the nads off your tdi in 2nd gear - it helps! Same offroad. As for them breaking.... yep, things break. Luckily in the 'majority' of cases, viscous fans break locked on. Thats a nice failsafe system if you ask me. Leccy fans fail off meaning you are screwed, Yes i have had one fail - on - and it sounded like a jet aircraft when being rev'd, but i didnt notice a great amount of power difference when i replaced it with a working one. As for engine heat up times in winter, i just sling a piece of card between the radiator and front grill, leaving a 6" gap on the left to expose the intercooler. heat up time therefore remains the same more or less. Quote Link to comment Share on other sites More sharing options...
mmgemini Posted November 15, 2011 Share Posted November 15, 2011 nicks90 I suggest you fit an EGT gauge. Then you won't scream an engine up hill. LOL... As for the card. That should be at the bottom of the rad. Notice I said bottom. Not the physical but the actual bottom. Quote Link to comment Share on other sites More sharing options...
CwazyWabbit Posted November 15, 2011 Share Posted November 15, 2011 Out of curiosity Mike, if you suffered a coolant loss do you think an EGT gauge would show the temperature change quick enough for you to avoid roasting your engine? Quote Link to comment Share on other sites More sharing options...
Lars L Posted November 15, 2011 Share Posted November 15, 2011 EGT changes waay faster than the water temp... And it is what it says, temperature in the exhaust only. Quote Link to comment Share on other sites More sharing options...
CwazyWabbit Posted November 15, 2011 Share Posted November 15, 2011 EGT changes waay faster than the water temp... And it is what it says, temperature in the exhaust only. Yep, that I knew but I probably didn't explain myself properly. I wondered what effect an overheating engine would have on EGT's and could this be used as a way to spot it? Quote Link to comment Share on other sites More sharing options...
Lars L Posted November 15, 2011 Share Posted November 15, 2011 Don't think so. Only way would be the coolant temp gauge, and a good one that actually shows the degrees, not just fields in different colours. I have a VDO that normally shows a fraction under 90 C. Without the fan and with a 2 ton trailer behind cruising in first gear (punctured trailer tyre...) was the first time I saw it go over 90. BTW, the fan is back in place again. Quote Link to comment Share on other sites More sharing options...
mmgemini Posted November 15, 2011 Share Posted November 15, 2011 No I don't think so. A EGT gauge tells you the exhaust gas temperature which if like me you were taught by drivers instead of driving instructors you would have been made to drive without either flogging or labouring the engine. Lars. My proper water temperature gauge rarely goes above 92Deg C. The themerature warning light conmes on at 94Deg C. Plenty of time to slow down if necessary. Is your temperature gauge a full face one? If not you don't see the half degree variation. LOL I can watch and see when my thermostat opens or closes when watching the coolant gauge. Getting the correct switch for an electric fan is one of the hardest parts of the job. Quote Link to comment Share on other sites More sharing options...
lrfarmer Posted November 15, 2011 Share Posted November 15, 2011 i got the disco engine in my 90 so the viscous fan hit the steering box and i can't get a cowling that would fit so i have a 14"fan on the rad, i dont need to the fan unless i towing and hard RTVs ( drove to hay-on-wye with the caravan on didn't need the fan on the motorway but once i got on the smaller roads i did need the fan) but i did have a 12" fan but towing the caravan overheated wasn't anuff air flow Quote Link to comment Share on other sites More sharing options...
CwazyWabbit Posted November 15, 2011 Share Posted November 15, 2011 Thanks for confirming what I had suspected, I shall be in search of a decent coolant temperature gauge then to cure my curiosity any recommendations? Quote Link to comment Share on other sites More sharing options...
tacr2man Posted November 15, 2011 Share Posted November 15, 2011 there are lots of other vehicles fitted with viscous fans , inc Toy@t*s , and they even have a dismantleable unit that you can by a little bottle of fluid to refill them !!. The fluid does deteriorate over time esp if subjected to high temps as happens in gaylander and others (sorento) visc couplings. If they fail in locked state (usual) then you need to be deaf not to notice the roar , in which case you either remove asap and keep the revs down untill you do , as that is what can cause blade fracture , although usually on pretty old units. Quote Link to comment Share on other sites More sharing options...
LandyLee Posted November 15, 2011 Share Posted November 15, 2011 just changed a viscous on a bmw because of lock up and blade failure . Only vehicle i see standard with an EGT sensor is the scooby WRX ,, and some newer diesels ,, never thought about fitting one to my defender , I suppose a rich mixture would show up as extra heat in the exhaust !! opposite to a petrols lean mixture Quote Link to comment Share on other sites More sharing options...
mmgemini Posted November 16, 2011 Share Posted November 16, 2011 Thanks for confirming what I had suspected, I shall be in search of a decent coolant temperature gauge then to cure my curiosity any recommendations? Most people aren't willing to spend money on a good temperature gauge. Get one with a full face dial that you can see the temperature changes in half degrees. One with a warning light that tells you when you are approaching the max temp you would like I went for an analogue gauge. The needle is set vertical for normal running temperature. That way i can easly notice any change in the reading. I have one of these. http://www.spa-uk.co.uk/design/productdetails/?objid=215 Might I suggest you sit down with a large drink near you when you look at the price. Quote Link to comment Share on other sites More sharing options...
nicks90 Posted November 16, 2011 Share Posted November 16, 2011 nicks90 I suggest you fit an EGT gauge. Then you won't scream an engine up hill. LOL... If i had a more powerful engine, i wouldnt need to give it some boot in 2nd gear to haul a heavy trailer up a stupid steep road at somewhere near sensible and safe speeds! Or i could crawl up the hill in low box 1st gear at 1500rpm with the slightest touch of the throttle - but the queue of traffic behind me might not appreciate that :-) Quote Link to comment Share on other sites More sharing options...
reb78 Posted November 16, 2011 Share Posted November 16, 2011 Might I suggest you sit down with a large drink near you when you look at the price. Good excuse to start early i think! When you compare to the cost of tachometers that are for sale, thats actually not too bad (especially considering its usefulness). Was the kit it came with all you needed to fit it Mike, or did you have to get other extras from elsewhere? Will the sensor they supply be a straight swap for a defender 200tdi one? Quote Link to comment Share on other sites More sharing options...
CwazyWabbit Posted November 16, 2011 Share Posted November 16, 2011 To be honest considering it is a quality gauge and sensor it isn't too bad, if you pay much less then you may as well stick with the stock gauge. The price is similar to an EGT kit which essentially consists of the same things just for a different temperature range. Quote Link to comment Share on other sites More sharing options...
mmgemini Posted November 16, 2011 Share Posted November 16, 2011 Good excuse to start early i think! When you compare to the cost of tachometers that are for sale, thats actually not too bad (especially considering its usefulness). Was the kit it came with all you needed to fit it Mike, or did you have to get other extras from elsewhere? Will the sensor they supply be a straight swap for a defender 200tdi one? I can't answer that because the sender fitted straight into the 300Tdi. I would suggest taking an old 200Tdi sender, drilling and tapping it out. So all in al. Gauge into dash. Use the original temp gauge wire as a live. Then take the lead to the sender into the engine bay. Fit sender and connect. I got the red gauge. I suggest you go for blue,then when you fit blue LED's into the other instruments, they match. Quote Link to comment Share on other sites More sharing options...
rick Posted November 16, 2011 Share Posted November 16, 2011 Talking of gauges a VDO mechanical gauge uses a thermowell that screws straight into the original temp sender location of a 300Tdi. You can watch the t/stat crack and modulate with one, and FWIW I'm with tacr2man, viscous fan all the way here. As he mentioned, Nissan Patrols and Land Cruisers have the ability to be opened and replenish/top up the viscous fluid too, we buy it in small sachets from a Toyota dealer. IMO they are more reliable on a working 4x4 than an elecktrickery one in this part of the world. Quote Link to comment Share on other sites More sharing options...
ashtray Posted November 16, 2011 Share Posted November 16, 2011 Ive had my viscous removed from my td5 since last winter! no problems with overheating at all. warms up slightly quicker in the morning and is "marginally" better on fuel. I have taken it up some pretty steep inclines for long periods at slow speed high revs and no issues so far! Quote Link to comment Share on other sites More sharing options...
crowmann Posted November 16, 2011 Share Posted November 16, 2011 Due to lack of time my plan to fit a 'bulkhead' within the engine bay has been put on hold. In principle I will hang off the radiator/intercooler cassette a bracket which will skirt the air flow as it passes through the radiators - I have an oil cooler, radiator and intercooler. Will isolate the air entirely from the engine bay - hopefully my electric fan will be ok as the air flow might be a little restricetd. Heres whats there at present: The idea is to better control engine temp in cold weather for use with my veg oil conversion as the real peril with Tdi's is them running too cold even when everything is tip top in cold weather conditions. Quote Link to comment Share on other sites More sharing options...
reb78 Posted November 16, 2011 Share Posted November 16, 2011 crowmann, can't you make your webasto maintain the engine temperature somehow? Some kind of thermostatically controlled switch to keep it heating below a given engine temp? Quote Link to comment Share on other sites More sharing options...
Troll Hunter Posted November 16, 2011 Share Posted November 16, 2011 My 110CSW was originally fitted with the V8 and with a/c. When I fitted a 300Tdi it didn't have the a/c compressor, so I removed the viscous fan unit and rewired the two a/c condenser cooling fans, mounted in front of the radiator, so that one would always come on with the ignition and would be running full time. This I ducted specifically to the intercooler. The second fan was switched by an X-Eng dual thermostat switch, located in the top radiator hose. Sorry, I can't remember the two thermostat switchiung temperatures. I then fitted a fairly large diameter, six bladed electric fan which was switched by the second (higher temperature) thermostat switch. I also had a warning light connected to this circuit. This large fan drew in excess of 25 amps. This set-up was fine, with the large fan very rarely coming on, and then only on long, slow uphill gradients when the vehicle was heavily loaded. I never suffered any overheating problems. I then had an Alli****t intercooler fitted, a small one that replaced the original unit, and had the FIP tweaked. At the same time I had an EGT gauge fitted. The probe for this is in the normally blanked EGR location, i.e. upstream of the turbo. This combination gave me significantly more power, and the EGT gauge has proved its worth. As previously noted, the response time for EGT can be only seconds, especially when under load, whereas the response time for the coolant is in minutes, due to the large thermal mass (assuming normal coolant level). No coolant temperature indicator will provide protection against high EGT and possible subsequent damage to the turbo. Having now moved from UK to BC, Canada, where hills are longer, and often steeper - try 10km at an average of 10% - I've found that my high temperature fan is on far more often, especially in 30+Degree summer temperatures, and I've occasionally had to stop to let the system cool down when towing. And yes, my radiator core is clean and relatively new, and the engine thermostat is working correctly. I've now removed the large electric fan, but kept the warning light in that circuit, and replaced the viscous unit, and I haven't had any overheating indications since. The small electric fan, switched by the lower temperature thermostat is still operational, and presumably reduces the periods that the viscous unit locks up, but I haven't checked that. Perhaps I should. If Kenlowe are claiming up to 8% more power available by fitting one of their fans, then that power can only be coming from removal of the viscous unit. The nominal power of a 300Tdi is 111BHP, or there abouts, so 8% is about 9BHP. There is no 12 volt electric fan that can match that power - something approaching 560 amps would be required - or the air flow resulting from a viscous fan. The 25+amps to my large electric fan generated a mild breeze compared to the viscous unit! So, for me, it's going to be viscous coupling fan for main engine cooling. I could try to get the best of both worlds, by refitting the large electric fan for winter use, and the viscous fan for summer use. That would be fine if there weren't a constant stream of other things to fix on my vehicle. As you all know, the LR work load expands to always exceed the time and funds available. Mike Quote Link to comment Share on other sites More sharing options...
farmerboy_y2k Posted November 16, 2011 Share Posted November 16, 2011 Ive had my viscous removed from my td5 since last winter! no problems with overheating at all. warms up slightly quicker in the morning and is "marginally" better on fuel. I have taken it up some pretty steep inclines for long periods at slow speed high revs and no issues so far! the standard temp gauge doesn't show fluctuations in temperature until the engine is actually overheating. if you plugged a nanocom or similar you'd notice the temp rising quite a bit on the digital readout. Quote Link to comment Share on other sites More sharing options...
lrfarmer Posted November 17, 2011 Share Posted November 17, 2011 http://www.ebay.co.uk/itm/280728697802?ssPageName=STRK:MESINDXX:IT&_trksid=p3984.m1436.l2649 i've got one of these fitted much better than the land rover one Quote Link to comment Share on other sites More sharing options...
crowmann Posted November 17, 2011 Share Posted November 17, 2011 crowmann, can't you make your webasto maintain the engine temperature somehow? Some kind of thermostatically controlled switch to keep it heating below a given engine temp? Well it certainly works to warm up the cab heater and the FPHE for the veg oil but they do use fuel and my focus is saving money - well at least as far as putting fuel in the tank. Last fill up courtesy of Mr Tesco (home delvered) was a full tank of veg oil for an average price of 78p per litre when I used some online discount codes - and bought 140litres. Not too shabby a saving over regular diesel of 60p a litre! Quote Link to comment Share on other sites More sharing options...
dailysleaze Posted November 19, 2011 Share Posted November 19, 2011 I've had 3 viscous fans fail, 1 Puma last week and 2 300Tdis. All were on 4-5 year old vehicles that had spent their entire lives in tropical/sub-tropical climates. All three didn't fail safe. One failed with the clutch open (didn't spin) and on the others the hub sheared off the nut. I'd still have one over electric though as they're easy to diagnose and easy to replace, and lasting 4-5 years in 30 degrees+ isn't bad. Quote Link to comment Share on other sites More sharing options...
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