You need to dump the 10w-30.
If the fan clutch it making noise when is it making noise? How long? Under what conditions?

 

Bearing whines for a few minutes on cold start. Fan functions fine. Did the same thing last winter, silent all summer. No physical signs of bearing failure. Shifted to lighter oil for the winter. Service record shows 10-30 exclusively for the first 50k miles at least. My first Disco 1 wasn't crazy about ?w40 in winter. If not 10-30, then what grade? I know what each number means, but my experience has never shown me that cranking effort with 10-40 is the same as 10-30 (especially @ 5 deg. F - it's coming). I'm sure the engine does not know it's 20 degrees out when on the expressway at 70mph for hours though.

 

The fan has no bearings in it, it is your water pump making the noise from the extra load on it, the colder it is when sitting all night/day the thicker the fluid inside the fan clutch, the thicker the fluid the harder to turn the fan.
Could be your fan clutch is on its way out, but def your water pump bearings are under strain.

10w-30 and 10w-40 are the same when cold, 5w-30 and 5w-40 are the same when cold.
Its when hot that you need the higher number.
No the engine does not know it is 20* out when driving, the engine is still going to be hot.
I ran 5w-30 one winter and my truck sounded like it had ball bearings rolling around in the crankcase when hot, nice and quite when cold, but at a hot idle it sounded horrible.
Switched back to 5w-40 and quiet as a church mouse once again, even when hot.

 

Since you're also in Michigan, what oil are you running?

 

Is it bearing whine for the first couple of minutes when cold or fan "roar" (which is normal)? Or is it your SAI pump cycling (makes a whine as it is about to poop out) - but that should only happen on cold start when air temp is abve 46 F and engine coolant is below 131 F. You can use a mechanic's stethoscope or a wooden stick pressed to your ear and the other end on the water pump to isolate the noise better.

 

I run Shell Rotella, 5w-40 in the winter, 15w-40 in the summer, 5,000 mile oil changes and NAPA or Purolator oil filters.
I run this oil in my wifes Volvo with a turbo as well as my mom's Ford Escape, all with 5,000 mile oil changes.
I buy it at Wal-Mart as they sell it cheaper than anyone else.

 

We're on the same page in summer (and WallyWorld). I'll give the 5-40 a shot. Thanks for the info.

 

Great call on the oil. My first "Hot" oil pressure values were high, I didn't get things really up to full temp. Pressure eventually dropped to 15/40 hot. I ditched the 10W30 for 5W40 and did an extended drive. Now consistent 22/48 with 5W40. Although subjective, clatter seems less. As for the fan, it whines a few minutes after dead cold start; low 30's and below. I know it's the fan, I stalled the fan and it stops whining with a slight side load on one of the blades. Viscous coupling is working per description in Rave. Made the same noise last winter, nothing in warmer months. Fan turns smoothly and has no bearing shake or wobble. Stethiscope also confirms it is not the water pump. I'll keep an eye on it; don't want a grenaded fan, radiator and hood. SAI pump is fine, it's my Rover's way of saying "Good morning". I'' bet it would make a great pump for blowing up air mattresses.

Thanks for the great info. I wonder if forums for other vehicles are as OCD - I'd like to think the rest of the world is just driving around wearing rose colored glasses (and carrying gold cards). Rovers are a hobby cars to be sure.

 

Fan clutch has silicone fluid inside lost or dropping in volume. Eventually it does not couple well and will freewheel when warm, cooling suffers at idle and slow road speed. Cheap to replace, write up in tech section. My practice has been if it spins more than 1 revolution when warm it is time for a new clutch.

 

There are forums for every car out there, even Camry's lol!
But I do think we are more OCD than most, maybe vintage cars are more so, I def know that oil guys are more OCD, those guys even spend $70 to buy a tool to cut their oil filters open after every oil change.