Discovery 1 Cooling Fan Saga

[GGRR 4555]

I was driving home from work the other day and decided to drop my Disco into 4low and run up in the hills. 20 feet up the hill I heard a loud bang that I thought was a rock kicking up into the fender. I backed down the hill and noticed the ground on the hill was wet. I hopped out to find my radiator was evacuating coolant rapidly.

Popped the hood and discovered literally hundreds of plastic shards. The cooling fan had shattered every single blade into many pieces and 85% of the fan shroud was also reduced to 100's of shards. I am still finding plastic in the engine bay. Any guesses why this carnage happened??? I suspect old motor mounts let the fan contact the shroud and they exploded.

Multiple plastic shards pieced the radiator.


So now with the need for a new fan, new radiator, and new fan shroud (which I had no idea how to find) I decided I would probably be better off coming up with an electric fan option. Also my rover is painfully slow so freeing up and power is appealing. I turned to the 1992 ford Taurus fan as I know they are a good two speed unit (16" fan) that guys put on jeep TJ's and ZJ's with success.

I shaved down the Taurus fan shroud so it would fit between the radiator and water pump snout. I also made a shroud to seal it up to the radiator. Photos show how it turned out. I used screws and sealant as I don't have a tig welder but I think it turned out nice and clean. Do you guys think it will flow enough air?

Next up is to wire the thing. I am trying to apply all internet wisdom to make sure the wiring functions properly and cant hurt itself. Wiring template I am using is attached as well.

Any thoughts?

 

[06h3]

Check your front body mounts too. The motor can move due to bad motor mounts but the body can be flopping around with bad body mounts. I think you will have better cooling at low speeds. Higher speeds will be tougher to tell. Someone with more cooling knowledge then myself can chime in on that.

 

[GGRR 4555]

Check your front body mounts too. The motor can move due to bad motor mounts but the body can be flopping around with bad body mounts. I think you will have better cooling at low speeds. Higher speeds will be tougher to tell. Someone with more cooling knowledge then myself can chime in on that.

Good tip on the body mounts! Didn't think of those.

 

[A4L7E3X]

It's not unheard of for Rover v8 fans to explode, it might have just been a case of in low range it was allowed to spin up a bit quicker and it let go.

I can't help specifically with the Taurus fan, but I run Ford Falcon thermo fans on my 3.9 Rangie (its a pretty common swap in AUS) and I never have a problem with coolant temps, and I was giving it a pretty hard time on some sand dunes a few weeks ago.

I wired mine up with a temperature probe though, the fan off LED is a good start, but I prefer to let a fan controller do the remembering for me. I did wire it up so that I can switch it off in case of a water crossing, but with the switch in the off position I wired up a very annoying buzzer so I wont accidentally forget.

 

[Dougal]

I've got some dual thermoelectrics wired up with a series/parallel switch.
Using the AC switches them in series for low speed, when the coolant temp switch comes on it switches them into parallel for full speed.

The switching is done by a double relay pack. It's probably harder than switching a dual speed fan like your Taurus.

 

[GGRR 4555]

She's Alive!!! I cant believe how much quieter the rover is. The mechanical fan sounded like a tornado driving from a stop. The new fan purrs. I have low speed on a thermostat and high speed on a switch. It is cold outside so I can speak 100% on the system yet but so far so good.

I made a panel to hang the breaker, relays, and thermostat behind the passenger headlight. The under-hood room on these things is limited!

 

[A4L7E3X]

If you noticed your old fan being noisy it's likely that the viscous coupling was seized, that's probably part of the reason your old fan exploded.
You might even notice an improvement in economy (not usually a term associated with Rover V8s...)

 

[BDK]

The Ford fans from the 90's used to develop large cracks in them, then shatter if not replaced.