How to Repair or Replace the Thermostat on a 1993 Chrysler Concorde

The thermostat on your Concorde controls the coolant flow from the radiator to the engine. Over time, the thermostat fails and it either remains stuck open, which causes over-cooling of the engine, or stuck shut, which causes the engine to overheat. Typical signs of a defective thermostat include a noticeable rise of the temperature gauge on the dashboard. Or, only cool air blows when the heater is on, even after the car has reached normal operating temperature. The thermostat is not a part that can be repaired with a few screws; if it has become defective, it must be replaced immediately.

Instructions

Removal

1

Loosen and remove the negative battery cable from its post with a socket wrench. Then position the cable away from the battery, engine, and any other metal it may contact.

2

Slide the coolant drain pan underneath the radiator on the right. Loosen the drain-plug at the bottom of the radiator by hand; do not fully remove the drain plug. Allow a quarter of the coolant to drain into the pan, and then re-tighten the drain plug.

3

Follow the top radiator hose over to the thermostat-housing cover. Squeeze the spring-tension clamp together with a pair of pliers, and pull it back on the hose four inches. Remove the hose from the housing cover by pulling it outward.

4

Remove the two bolts holding the thermostat-housing cover in place with a socket wrench, and take the cover off. Lift the thermostat straight out of the intake manifold and discard it.

Installation

5

Clean the mounting surface of the thermostat housing and around the intake manifold. Use a flat-head screwdriver to carefully scrape off any remaining pieces of the old gasket if need be.

6

Moisten the new thermostat gasket with cool water, and then place it into position on the intake manifold. Insert your new thermostat, spring down, into its position in the manifold.

7

Place the thermostat-housing cover back into position on the manifold. Then start both of the cover's retaining bolts by hand, to assure proper threading. Set your 3/8-inch-drive torque wrench to 21 ft-lbs., and completely secure both bolts in place.

8

Reconnect the top radiator hose to the thermostat-housing cover, and then return the spring-tension clamp to it original position to secure the hose.

9

Connect the negative battery cable back to its post, and tighten its retaining bolt until secured. Properly refill your cooling system, then start the Concorde's engine and check the repair for any noticeable leaks.