I have a 2004 Disco II with 59,480 miles. When starting the engine from dead cold, I hear a whining noise that speeds up with revs and goes away (as best I can tell) when the engine warms up. I suspect the water pump as I noticed a little shaft play when changing the serp belt last week. But my question is... could it be the viscous drive/fan itself? Atlantic British has both Water Pumps and Viscous drives on sale... but if you guys agree that it can't be the viscous drive I'll just order the pump (and save $239). Can't blame me for wanting to save a few bucks! Thanks for the help in advance!

 

It's not your SAI is it?

 

I am familiar with the SAI sound. That is not what I am hearing. I freaked out when I first heard the SAI pump though, my last Disco didn't have it. Thanks for the suggestion.

 

The fan is supposed to come on when the engine is cold and has been sitting over night for example, totally normal.
The viscous clutch is full of fluid and it settles when it sits for a long time, once it is running and the fluid gets warm the clutch will unlock.
Next time the truck has sat all night or after work open the hood, start the truck and then stick you head under the hood next to the side of the engine.
If your hair is being blown around like you are in a Nebraska then it is your fan clutch being locked up from sitting.
If it does it all the time then you need a new fan clutch.
Also find out if your truck has secondary air or not.

 

Hi Spike, So if I have this straight -- the fan should stop spinning once it is warm? Or at a slower RPM? I do have SAI, but the shop-vac like pump sound is not what I am talking about. To describe the sound as best I can -- it sounds like a high pitched grinding sound that subsides after running for around 5-10 minutes. And as I mentioned -- it is RPM variable. I have not run the truck with the belt off to check, but there was play in the water pump shaft. Thanks for the help, I really appreciate it.

 

The fan will spin any time the engine is running, BUT it will spin at the same speed as the engine when the fan clutch is locked, like when cold after sitting all night or when the engine is to hot.
When the fan clutch is locked it will put extra strain on the water pump.
Since you have play in your water pump shaft it is only a matter of time before it comes out of the pump and the fan goes through your radiator.
Yes that does happen, not often, but it does.
Remove the belt, start the truck, no noise?
Turn the truck off, spin water pump by hand, noise?
Replace water pump and fan clutch at the same time.
You can buy a water pump off of e-bay for $100 or so, and a water pump from a '96-'04 are the same.
So a '98 DI water pump will fit your truck for example.

 

Thanks for the help Spike. I have been watching it for a week or so and the fan clutch appears to be ok. I received the water pump (I had already ordered it) from AB yesterday. I am going to look around and see if I can find the clutch for less than $239 (Maybe Paddock?) Thanks for all the help!

 

Autozone sells the replacement and an HD version that locks up sooner. I would suggest the OE replacement. I have the HD and it feels like it locks up too much. $99..

 

Like OK said do not use a heavy duty fan clutch on your truck, it will lock up all the time and suck your gas mileage.
I bought mine used for $50.
www.autosportsunlimited.com