Chrysler Front Wheel Drive Cars 4-CYL 1981-1995 Repair Information

Thermostat

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REMOVAL & INSTALLATION



Except Premier

See Figures 1, 2, 3, 4 and 5

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Fig. Fig. 1: Exploded view of the thermostat housing, thermostat and gasket-2.2L and 2.5L engines (except 2.2L Turbo III)



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Fig. Fig. 2: Exploded view of the thermostat housing, thermostat and gasket-2.2L Turbo III engine



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Fig. Fig. 3: After draining the coolant, detach the radiator hose from the thermostat housing ...



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Fig. Fig. 4: ... remove the housing, then pull the thermostat out of the water box



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Fig. Fig. 5: Make sure to clean all old gasket material off of the water box

The thermostat on the 2.2L and 2.5L engines is located in the thermostat housing on the cylinder head, next to the distributor. On 2.6L engines, the thermostat housing is located near the intake manifold.


CAUTION
Do not loosen the radiator drain with the system hot and pressurized because serious burns from the coolant and steam can occur.

  1. Drain the cooling system to a level below the thermostat.
  2.  


CAUTION
When draining coolant, keep in mind that cats and dogs are attracted by 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.

  1. Remove the upper radiator hose clamp, slide the hose clamp away from the end of the hose, then disconnect the hose from the thermostat housing.
  2.  
  3. Remove the oil dipstick bracket retaining nut from the thermostat stud. Pivot the oil dipstick bracket away from the thermostat housing.
  4.  
  5. Remove the 2 mounting bolts (one is a stud/bolt), then remove the thermostat housing.
  6.  
  7. Remove the thermostat and discard the old gasket. Clean both gasket surfaces thoroughly.
  8.  

To install:
  1. Lightly coat the gasket with a high-tack type gasket cement to hold the gasket in position on the water box. Position the gasket on the water box so that the bolt holes are aligned. Position the thermostat on the water box, making sure it is properly seated by centering it on top of the gasket. Install the thermostat housing over the gasket and thermostat, then install the 2 mounting bolts. Tighten thermostat housing retaining bolts gradually to 21 ft. lbs. (28 Nm).
  2.  
  3. Reposition the oil dipstick so that the bracket is installed onto the thermostat housing stud. Install the bracket retaining nut and tighten it until snug.
  4.  
  5. Reconnect the upper radiator hose. Install and tighten the hose clamp. For more information on cooling system hoses, refer to Routine Maintenance .
  6.  
  7. Refill the cooling system, start the engine, and check for leaks. After the engine has reached operating temperature, allow it to cool. Then, recheck coolant level in the radiator, refilling as necessary.
  8.  

Premier

See Figures 6, 7 and 8

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Fig. Fig. 6: Before removing the thermostat housing, remove the upper radiator hose, the intake manifold hose and the coolant temperature sensor connection



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Fig. Fig. 7: The thermostat must sit flush in the groove in the cylinder head when installing the housing



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Fig. Fig. 8: An exploded view of the thermostat housing, thermostat and gasket

When servicing the thermostat, do not allow coolant to drip onto the accessory drive belt and/or accessory drive pulleys. If coolant does contact the drive belt or pulleys, flush them with clean water.

The thermostat is located at the front of the cylinder head, behind the thermostat housing.


CAUTION
Do not loosen the radiator drain with the system hot and pressurized because serious burns from the coolant and steam can occur.

  1. Drain the coolant from the radiator until the level is below the thermostat housing.
  2.  


CAUTION
When draining coolant, keep in mind that cats and dogs are attracted by 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.

  1. Disengage the coolant temperature sensor wire connector from the sensor.
  2.  
  3. Remove the upper radiator hose and intake manifold hose (heater hose) from the thermostat housing, as described in Routine Maintenance .
  4.  
  5. Remove the thermostat housing retaining bolts, then remove the housing, thermostat and old gasket from the cylinder head.
  6.  
  7. Clean all of the mating surfaces completely.
  8.  

To install:

An arrow or the words "TO RAD'' is stamped on the thermostat to indicate the proper installed position.

  1. Install the thermostat into the recess in the cylinder head with the air bleed valve up and the pellet, which is encircled by a coil spring, facing the engine. Thermostats are marked on the outer flange to indicate the proper installed position.
  2.  
  3. Install a new gasket and the thermostat housing to the cylinder block.
  4.  


WARNING
Tightening the thermostat housing unevenly or with the thermostat out of its recess can result in a cracked thermostat housing.

  1. Tighten the housing bolts to 13 ft. lbs. (18 Nm).
  2.  
  3. Install the radiator upper hose and intake manifold hose to the thermostat housing. For more details, refer to Routine Maintenance for correct hose clamp positioning and tightening procedures.
  4.  
  5. Make certain that the radiator drain plug is closed.
  6.  
  7. Attach the coolant temperature sensor wire connector to the sensor.
  8.  
  9. Fill the cooling system with a 50/50 mixture of water and antifreeze.
  10.  
  11. Start the engine and check for leaks. Allow the engine to reach normal operating temperature, allow it to cool back down and refill the cooling system, if necessary.
  12.  

Cooling System Bleeding
EXCEPT PREMIER

To bleed air from the 2.2L and 2.5L engines, remove the plug or sensor on the top of the thermostat housing. Fill the radiator with coolant until the coolant comes out the hole. Since the plug is made out of steel and the thermostat housing is aluminum, it is a good idea to apply an anti-seizing compound or Teflon® tape on the plug threads prior to installation. Install the plug and continue to fill the radiator. This will vent all trapped air from the engine.

PREMIER

Slowly fill the cooling system at the coolant pressure bottle until the coolant level settles at the full mark. Start the engine and allow it to run until the upper radiator hose is warm to the touch. Turn the engine OFF and ensure that the coolant level in the coolant pressure bottle is at or slightly above the full mark (at the top of the post inside the coolant pressure bottle).

The full mark on the coolant pressure bottle is the correct level for a cold engine. A hot engine will normally have a coolant level higher than the full mark.

 
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