Originally Posted by JeepMe
Check the fan and make sure it is kicking on both speeds. When you start the Jeep from cold it should come onto low speed. Once it gets to operating temperature it should engage into a second and you should hear a difference (it's VERY noticeable). If you cannot hear the fan change speeds, that's your problem.
Excellent point on that cold start fan noise. It should sound extremely loud when started after being left off some time. Don't recall the time it takes, but first thing in the morning the very first start should result in a rather loud roar from the fan that goes away reasonably quickly.
I'd spend the money for a professional flush before springing for a radiator.
Or get a good reverse pressure flusher...
Just because the water is clear doesn't mean there isn't a possible plugged coolant passage either in the block, or in the radiator. Theoretically it is possible to take
the radiator apart and clean the passages... never tried it with a plastic tanked one.
When you finally fill it, make sure you replace any weak hoses, and burp every one thoroughly, or fill it from the bottom drain and a pump.