I've got it at an indy shop close to the house. Waiting to hear back from them soon.

 

I'd suggest you get yourself one of these, UltraGauge Automotive Information Center and OBDII Scan Tool (or at least something similar). It gives you a digital read out of your engine temp (plus it reads codes ect), having one of these saved me from driving my truck with a buggered thermostat which in turn prevented me from trashing my engine. I noticed it was on its way out because my truck all of a sudden started running 10 degrees warmer than usual however the temp gauge didn't budge at all.

 

I didn't drive in disco to work today, so it is parked on the street, but how do I check the viscous fan clutch?

I have read the mixing dexcool with other coolant is not a good idea, I am afraid that this might have happened, a local indy was suppose to flush my dexcool coolant and change the T-Stat. The T-stat has been changed but the coolant was still the orange one, he states he flushed it with the same color coolant, i am afraid he might have topped it it off after thermostat change with water or other type of coolant. This is the reason why I want to flush it myself this time.

Can anybody tell me if I could leave the flush in for a day or so? I will be changing the T-stat to the soft spring low temp one anyway.

 

Follow direction on the flush product exactly.

To check fan clutch - with engine cold, not running - spin fan and release. Should go maybe 1/4 to 1/2 turn. Should feel like peanut butter inside the clutch. Then warm up truck to normal temp, and turn off. Spin by hand and release, again it should stop in less than 1 revolution. If it freewheels, the clutch has lost the fluid inside, and needs to be replaced, write up tech section for a $50ish Chevy cross over.

Don't try the shop trick of grabbing the fan to see if you can stop it while engine running - too many mechanics are called "Stubby". Also check your belt route (shown in tech area). Like Discover Discovery Maintenance Tips, Accessories, Parts & More at Roverparts.com

 

some of those flushing agent are very strong and not only with the block the t-stat they can also block the heater core.
Most state to shut the heater off before flushing, well with all of LR wisdom there is no way to shut the heater off.
You "may" want to flush it using bottled water and white vinegar either way you will probably either have to remove the t-stat or replace it when done.

 

Here's pix of the little holes that can get gunked up in the stat when flushing, they sample the hot coolant and make the thermsotat open. Restrict them, and stat opens later than it should. Pix of radiator dex-mud, and calcium build up (well water, tap water). Usually when things get to this point, flush is not enough. Also, mud in the fins of radiators, AC condensers, tranny coolers, oil coolers - all can cause heat issues. But getting the mud there is obviously great fun.

 

Yes, yes it is.

 

The fan seems to be fine, turning no more than half revolution when cold, there were places when the fun was turning with less resistent and than again more resistent when cold. After driving the truck to work and trying to turn the fan, there was a consistent feel and was not turning more than 1-2 blade legnth at time.
I got the prestone reverse flushing kit, I hope that cutting into the heater core tubing, which is a relatively short piece wont cause any problem.
Instruction for flush states to drain the radiator first, and than put the flush and fill it up with water. I don't know if it works better with water or why? Prestone instruction does states to turn the heater to high and let the engine run until operating temp.

 

Here's the flow path for coolant, heater core path may reverse the heater core, but might not do much for radiator in reverse direction.

 

Just pull the lower hose and dump it, it will take days to clear out the system using the reverse flush thing.