'90 V8 Overheating

[Reynard8@aol.com]

Help!  My wife's "new" car has this problem:  

Even with the electric fan jumped to run constantly at high speed the engine
overheats to boiling unless its reved over 2,500 rpm, then it slowly cools
down.  The former owner replaced the thermostat and I just installed a new
water pump.  Now overheat takes somewhat longer to occur so I'm considering
radiator reconditioning and a check for restricted hoses.  The belt-driven fan
turns but maybe the viscous clutch is shot?  Anyone BTDT??

Joe Fox
'90 V8 Auto
'97 BMW 540 ia (for sale)
'55 Ford Pickup 351C/C6 Auto