I just bought a 2000 jeep grand cherokee 4.0 straight 6 it

If the fans don't come on to cool the radiator then maybe it's the thermal fan switch, which sends the turn on signal to the fan relay, that might be bad.

fan motor broken ,,or feel pipes from rad when jeep is running for a while,pipes must be hard ,if soft problem is with pipes broken split ,ect ect,

That is normal, the system is designed this way to prevent the overheating of the engine's head when you shut down the engine without allowing it to cool itself to an acceptable temperature.

The timing is determined by the Power Control Module (computer) by reading the crankshaft position sensor. There is no adjustment possible. The only service possible is replacing individual components.

straight from the Jeep service manual

1.) Disconnect negative battery cable.
2.) Remove screws attaching front of overhead console to front of bracket.
3.) Pull console downward from area near courtesy lights. 4.) Disconnect electrical connectors and remove console from vehicle.

To install, reverse removal procedure.

electric fans or belt driven? if electric are they kicking on?

If you are reusing the same manifolds and just mainly using the block and head you should be fine.

I wrote all engine spec for a 2005 jeep grand cherokee

3.7L 6 cylinder
1-6-5-4-3-2

4.7L 8 Cylinder
1-8-4-3-6-5-7-2

5.7L 8 Cylinder
1-8-4-3-6-5-7-2

let me know if this help you.....

Usually the electric fan(s) are temperature activated. I would look into the temp switch. If you're not sure what it is, go to the auto parts place and ask for one. This way you can look at it then hunt for it under the hood. It usually screws into the engine in the cooling system. Also, make sure the fan has a good ground. Check for power to the fan when the engine warms up. If you have a/c, turn it on and the fan should come on whether the engine is warm or not.

Hope this helps. Good Luck

It's behind the passenger headlight.Need to take off grill,bumper fascia to get access to it.Mine took about an hour alltogether.