That's basically what they told me, too. When my single fan setup comes on at stop it lowers Temps FAST. IMHO, two single fan setups would draw too many amps, if there was any way to fit them. My single fan draws 18 amps and the wind from it can easily be felt on your ankles near the driver door. It blows so much wind, my engine is cleaner.

I had a spare top shroud and cut it a little to fit over the gap between the chassis and the radiator thinking that the space would make it really easy for hot air to be sucked back across the radiator but didn't use the lower portion of the shroud to be sure that I got enough air around the single fan aluminum shroud. Seems to keep my temperatures Okay at speed and at stop, even though it is in the mid 90's outside.

 

Charlie, how had this been working out for you? I'm a bit hesitant to pit the single in, with the shroud being the way it is..what do you have your temp set to and what are your temp running?

 

My temp is set at 205 as measured by the temperature that my intake provides to my scan tool. When the fan comes on, the temperature goes down quickly. It pulls A LOT of air. As I've said previously, you can feel it on your ankles at the driver door and it is so much air it is keeping the dust off of my engine.

I defer to Dusty and many others on everything Rover. And automotive... they are just more knowledgeable than me. But if pressed, my personal opinion is that a full shroud with these fans could hinder cooling on the highway. These fans have closely spaced, swept blades and the shroud is aluminum and fairly flat across the back of the radiator. At a crawl or stop, a full shroud is going to pull more air across the radiator. At highway speed, no shroud and no fan is what you want. When I got my new fan/shroud out of the box I thought "WTF™ is this? It is too small. Is this universal?!" but when I contacted the seller and then checked the manufacturer's site, it made more sense.

Just yesterday I got the last piece for my inline thermostat and I will probably put it all together today. With that on I'll check my temps again. I'm expecting big things from the combination of the inline thermostat and electric fan. I'll let you know what I find.

 

The dual fan is rated at 3000cfm and the single at 4000cfm. Just redid the cooling system, new water pump, radiator, belts and hoses. i had replaced the T stat with a 180 a couple of months ago.

I just finished the conversion and drove the car this morning. While driving free of traffic the temp ran 186.8 to 188.6. Outside temp Low 80's. Even with traffic the temp never exceed 197.6 so the fan never kicked on.

Ran another errand this afternoon and it ran a little hotter, outside temp mid 90's engine ran around 190.4 and 194.0, again not much traffic.

Returning, outside temp high 90's engine ran up to 204. staying between 201.4 and 204 . Stopped at the mailbox and then a slow drive down the driveway. Pulled in and adjusted the fan to come on at 208 so it would not be running continuously. Sat in the car for a while watching the temp and it continued to climb up to 215, when I shut it down. The same symptom seemed to be happening with the original fan which partially prompted the change.

Any insight?

 

Did not drive it today. Had to go up IH35 and that can become a parking lot. Got back and raised the header tank to check the system bleed. No air out of the bleeder screw. Left the tank raised and started the engine. Got a ping pong size bubble out of the hose that connects to the bottom of the tank. Ran the engine with the AC on and doors open to increase heat load. Ran up to 206.6, fan kicked in and back down to 199.8 where the fan turned off. Repeated multiple times, ambient temp read 94.

Can that small an an air bubble cause that much trouble. Never have run into something that small causing problems usually they will just work their way out.

 

Do you have the right coolant in the disco. I believe someones son had put the wrong type in his and it ran hot.

 

That was mine. He put straight antifreeze in.

The "heat sink" effect is pretty extreme in our trucks. Get it up to temp that stop, note the temperature, and turn it off. Come back a couple of minutes later and turn the ignition on so you can get a temperature again and it will be a few to a bunch of degrees higher. The temperature sensor is on the stop of the engine and heat just migrates to it.

Herb, spray some degreaser on your radiator and get it good and clean. At the very least your air conditioning will be twice as effective (if the condensor is dirty). Getting to the radiator is harder but with enough degreaser and water it will make a difference.

I really don't think that a small amount of air would make a huge difference but the best would be for no air to be in the system except in the expansion tank.

 

The radiator is new, will clean the condenser just in case. I am running the Peak Global Life Time antifreeze with Royal Purple Purple Ice as was recommended on the forum.

 

I am always messing with my Disco. Recently, I have had a problem of VERY high temperatures on the highway. I have the single fan setup. As detailed elsewhere, I recently got a 2003 in poor shape to swap the larger 4.6 engine and hp24 into my 2000 Disco II, so I have alot of extra parts.

When I say high, I saw 226 degrees. It only cooled down when I slowed down and, with the electric fan on, got back into the 180's pretty quick. I had one miserable day this week where I had to drive a considerable distance with the heater on to save the engine (ambient temp was 98-100 and I was in a suit--not a happy camper), then my throttle cable broke (unrelated) and I had to IDLE home 4 miles in 4low (for hills), again, with no air con. So I have been doing a few things to try to isolate the problem in preparation for my 4.6, which is at the shop. I have a little circuit that I drive to test temps that starts at about 45 miles per hour with few lights (5 mins), then 75 mph with hills for 10 minutes, with a turnaround in the middle, then 5 mins back at 45mph.

Herb, you aren't crazy.

Here is what I did:

1. Did the inline thermostat mod. Ran it with and without a thermostat. My temps kept climbing on the highway so I tested the thermostat, bought another, and tested it (in water on the stove); they worked. The high temp with and without a thermostat was the same (about 216). Still, this was 10 degress better than the normal thermostat... I highly recommend it.

2. Replaced the water pump. When I took my old one off I immediately knew that was a mistake because it looked great. I already had the new one in the garage so all it cost me was time and a gasket, but still. I ran the circuit, and got the same temps.

So it is my radiator, right? I ordered one. But before the new one arrives:

3. Flushed the radiator and engine and heater core mercilessly. Used chemicals. Used vinegar. Nothing came out. Still, it HAS to be the radiator, right? After all of that, the temps were 2 degrees cooler. High of 214. No good.

4. Swapped the radiator from the 2003 into my truck. This radiator had dexcool in it so I flushed it mercilessly. I went ahead and did the swap and I am glad I did because it didn't occur to me that the transmission cooler would be bigger for the hp24 (it is), so I swapped in this completely junked out, beat up radiator, that looked like gorillas had been given wrenches and a cage to beat it in. Probably 5% of the fins are bent to hell on each side, which adds up to ten percent because they don't match up. New temp? 208. I am getting somewhere. But 208 when I have a 180 thermostat at the inline mod? Ridiculous! And it CLIMBS on the highway. Anyone who has pulled the radiator and condensers and made that huge mess, had to deal with the compression fittings, etc., knows that I am getting pretty worked up at this point in the diagnosis. Cuts on my hand, antifreeze in my mouth from the flashlight. You get the picture.

5. HERE IS THE IMPORTANT PART, FINALLY. I cut the wires and ties for the electric fan and put my old mechanical fan in. No shroud. High temp? 194. BINGO. THE ELECTRIC FAN SUCKS ON THE HIGHWAY, metaphorically, and DOESN'T SUCK ON THE HIGHWAY, literally. The electric fan's flat shroud is keeping air from passing through the radiator! I replaced the OEM upper and lower shroud and the temp on the highway dropped another two degrees to 192. Same stretch of road, roughly same temperature (within three degrees), same driver, same truck. The electric fan shroud inhibits cooling at highway speed. Period. I have an indicator light connected to my fan; I know when it is on and off; highway temps went up quickly whether it was on or off.

The electric fan is a wizard at bringing your temps down at idle and around town, but on the highway it is absolute JUNK.

Now, I still think I need a new radiator (which is convenient because I already ordered and paid for one), but the electric fan is gone for good.

Dusty has had good luck with his, but he runs a tight ship and has an electric water pump (if memory serves). I am just a regular Joe, Land Rover wise, and run a loose ship, so, for me, the electric fan is only for crawling on trails, if at all. My around town temps dropped to 187-190 and my highway temp is now 192. That's a pretty stark difference from 208 and beyond in testing and, obviously, the difference between a cracked, warped, or de-head-gasketed engine.

 

This was an excellent post Charlie, and I appreciate you sharing it. I shows that your shroud is the restriction an is something we should all look out for when installing electric fans.

I run dual electrics on my daughters and the only issues we have is when pulling the boat on a hot day - can't run the AC. Normally runs about 190-200 on the highway and in traffic with the electrics - never really thought about the shroud restricting it.