Originally Posted by cgalpin
Genuine? I went through this, having tried cheap cross-referenced ones, a non-genuine aftermarket (I forget but whatever AB/RN sell that's not genuine) and finally bought a genuine one. Only the genuine one doesn't howl unnecessarily. It will initially on a cold start as you pick up the revs then acts as you'd expect.
Not sure about the A/C fans coming on though - this would indicate your temps are higher and this might justify your viscous fan kicking in.
I think the after market is named "pro Line".
hot running issues can be one of the worst to solve, on one hand you need heat for the engine to run properly but too much heat your'e doomed.
then the maybe this maybe that approach just gets expensive and yields little and exhausting results.
we need to understand that our trucks are getting old so not all components work as designed, further more the maintenance given to them as they have aged just does not fully adress the aging issues.
defective exhaust system will cause issues, just flushig the coolant does not fully clean the cooling system...a better approach is to have the radiator cleaned in an acid bath at a reputable rad shop, the ideal and proper approach is to install a new unit.
thermostat is overlooked as well.
radiator caps if not functioning properly will not allow the system to pressurize and mantain a proper boiling point.
collapsing hoses, lack of air circulation the latter due to mud an debris trapped infront of rad and behind the ac condenser.
damaged cooling fins can block air passage thus reducing air flow.
defective fan clutches are a contribuitor.
at high mileage, the air fuel mixture can be improproper and the combustion chamber can be running at higher temps than designed.
too thick oil weight can cause drag thus converting to heat.
lack of oil changes yield the same effect as well.
dragging driveline components can cause the engine to simulate constant under load conditions, bigger tires, under inflated tires contribute as well.
so in a nutshell solving hot running conditions can be frustrating... it is not as simple as replacing one magic component and voila youre done.