Sounds like it is air bound, there is a bleeder on the thermo housing and
the bypass pipe. 3.1?

On Mar 16, 6:36 pm, baja...@yahoo.com wrote:

Probably an air-lock.  Did you bleed the air out?  For some cars there
is a set procedure to follow.

- On the 3.1L engine open the air bleed vent on the throttle body
 return pipe (above the coolant pump). The air bleed vent should be
 opened two to three turns.  
- [image: http://www.autozone.com/images/upper_left.gif]  
- [image: http://www.autozone.com/images/grey_line.gif]  
- [image: http://www.autozone.com/images/upper_right.gif]  
- [image: http://www.autozone.com/images/clearpixel.gif]  
- [image: http://www.autozone.com/images/clearpixel.gif]  
- CAUTION[image: http://www.autozone.com/images/clearpixel.gif]When draining
coolant, keep in mind that cats and dogs are attracted to ethylene
glycol antifreeze, and are quite likely to drink any that is left in an
uncovered container or in puddles on the ground. This will prove fatal
in sufficient quantity. Always drain the coolant into a sealable
container. Coolant should be reused unless it is contaminated or
several years old. [image:
http://www.autozone.com/images/clearpixel.gif][image:
http://www.autozone.com/images/clearpixel.gif][image:
http://www.autozone.com/images/lower_left.gif][image:
http://www.autozone.com/images/grey_line.gif][image:
http://www.autozone.com/images/lower_right.gif]
 
- Remove the drain plug(s) from the engine block (located on the
 engine block, above the engine oil pan) and allow the coolant to
 drain.
- Close the radiator drain fitting and reinstall the engine block
 plugs.
- On the 3.1L close the bleed valve on the throttle body.
- Add clear water to the system until it is filled.
- Start the engine and repeat steps 7-12 until the drained water is
 almost colorless. Turn the engine -OFF-.
- Allow the system to drain completely and repeat step 10. Remove the
 cap from the coolant recovery tank, leaving the hoses connected to the
 cap.
- Unbolt and remove the coolant recovery tank, drain it, and flush it
 with clear water. Reinstall the tank.
- Fill the radiator to the base of the radiator filler neck with a
 50/50 mixture of coolant/water. On diesel equipped models, add a
 gallon of undiluted coolant first, then add the 50/50 solution.-If only the radiator was drained, use a 50/50 solution to refill it,
then check the freezing protection after the level stabilizes.-
 
- Fill the coolant recovery tank to the FULL mark with the 50/50
 solution.
- With the radiator cap still removed, start the engine and allow it
 to idle until the upper radiator hose becomes hot, indicating that
 the thermostat has opened.
- With the engine still idling, fill the radiator to the base of the
 filler neck with the 50/50 solution.
- Install the radiator cap, being sure to align the arrows on the cap
 with the overflow tube.
- Turn the engine -OFF-, check for leakage, and double check that the
 radiator drain is closed and the drain plug(s) is (are) tightened.Dunno if this helps, but wth.