The only thing I can think of that would cause this is if the antifreeze is old or weak or diluted down with too much water. Try the following:
DRAIN & REFILL
Fig. 1: Remove and drain the reservoir recovery tank
Fig. 2: Location of the radiator draincock
Fig. 3: Use your hand to unscrew the plastic draincock
Fig. 4: To refill the recovery tank, twist the cap . . .
Fig. 5: . . . then pull up to remove it from the tank
Fig. 6: Adding coolant to the reservoir bottle
Fig. 7: Always check the condition of the radiator cap gasket and seal. Place a light coating of coolant on the seal and gasket when installing
When draining the coolant, keep in mind that small animals and domestic pets are attracted by ethylene glycol antifreeze and may attempt to drink any that is left in an uncovered container or from puddles on the ground. This can be fatal if ingested in sufficient quantity. Always drain the coolant into a sealable container. Coolant should be reused until it becomes contaminated or several years old. To avoid injuries from scalding fluid and steam, DO NOT remove the radiator cap while the engine is running or if the engine or radiator is still hot.
- Before draining the cooling system, place the heater's temperature selector to the full WARM position while the engine is running.
- Turn the engine off before it gets hot and the system builds pressure.
- Make sure the engine is still cool and the vehicle is parked on a level surface.
- Remove and drain the reservoir recovery tank.
- Place a fluid catch pan under the radiator. Turn the radiator draincock counterclockwise to open, then allow the coolant to drain.
- Remove the radiator cap by performing the following:
- Slowly rotate the cap counterclockwise to the detent.
- If any residual pressure is present, WAIT until the hissing stops.
- After the hissing noise has ceased, press down on the cap and continue rotating it counterclockwise to remove it.
- Allow the coolant to drain completely from the vehicle.
- Close the radiator draincock.
NOTE: When filling the cooling system, be careful not to spill any coolant on the drive belts or alternator.
- Make sure the heater temperature is placed in the full hot position.
- Open the bleed screw on the thermostat housing.
- Install the reservoir recovery tank and using a 50/50 mixture of the recommended antifreeze and clean water, fill the cooling system reservoir tank to the FULL mark.
If any coolant is spilled on a painted surface, wipe it up immediately.
- Begin filling the radiator with the 50/50 mixture of coolant. Watch for air being released from the open the bleed screw on the thermostat housing. Once coolant mixture begins to steadily flow through the bleeder, close the bleeder.
- Continue to fill the radiator until the radiator is full.
- Start the engine and allow the engine to run until the cooling fans operate two times, making sure to top off the system as the fluid level drops.
- After the cooling fan has run for the second time, top off the system as necessary, then install the radiator cap.
- Allow the engine to run and inspect the cooling system for leaks.