Im going to touch down lightly here on your topic of the fan speed. I too have that problem one of many of my lil problems but Ive found out that I have a loose wire where it plugs into. But when it warms up Ill fix that as well. But if you run into that problem again. Check your wires. Just my 2 cents

 

The oil pickup on the 2.9 is known for getting clogged. The OEM cam, main, and rod bearings are a poor design / quality and are known for premature wear. This, along with other design-induced problems causes starvation of lubrication. Depending on how far you wish to tear into yours, there are ways to make the situation somewhat better. I've found that flushing the engine prior to changing oil and using the recommended oil (5W-30), Purolator filter, and the cheapie Rislone engine treatment helps a LOT. I went as far as doing an engine flush with the existing used oil and new cheapie filter, draining, refilling with cheap oil and flushing agent, flushing again, draining, and another flush cycle, and THEN putting a new Purolator filter and 5W-30 Castrol in - and believe me, things were a lot quieter and my idle and @ speed oil pressures changed for the better. I had previously tried everything else others recommended except 15W-40 and noted that 10W-40 and 20W-50 and (guessing here) Fram filters just did not work well and the thing was noisy as hell. Even the owner's manual says that some tick is 'normal' on these things.

There are permanent fixes for the valvetrain tick, if you'd rather do that (but you have to do them all at once, otherwise you're wasting your time):

1) New 'better design' replacement bearings
2) New lifters
3) New oil pump
4) Completely clean the oil pan and oil pickup screen / tube
5) Install the cam thrust plate upside down -
(forget if this is required with the new bearings?)

Personally, IMO, if you're going to do all of that, you might as well have it all chemically cleaned and do a quickie overhaul of the engine, but you can get by with just that. Might even want to consider a mild RV cam or other mods while you're in there