How to Replace the Thermostat in an Chrysler Cars

by Contributing Writer; Updated June 12, 2017

Keeping up with routine maintenance is important if you want to keep your Chrysler car working properly. Although your ride might be starting to get a few miles on it, there is no need for things to feel less luxurious. Don't forget how important the cooling system is. The cooling system is your Chrysler car lifeblood; and if the thermostat has been ignored since the car was new, it could fail, causing your Chrysler car cruiser to suddenly become tomorrow's junkyard special.

Under The Hood:

 How to Replace the Thermostat in an 2004 Optra

Ensure that the engine and cooling system are cold. Open the drain cock at the bottom of the radiator and let the coolant drain into the pan. Unscrew the radiator cap to release any vacuum on the system. Remove the upper radiator hose at the thermostat housing using a pair of pliers to compress the retaining clamp. Remove the capscrews holding the thermostat housing to the cylinder head. Remove the thermostat and seal from the housing by pressing the mounting flange down and rotating the thermostat clockwise.

Inspect the thermostat housing for small pits and cracks. If present, replace the housing to prevent leakage. Clean the housing, the cylinder head mating surface and the capscrews with a small brush, cleaner and rag. The radiator hose should be clean and pliable without any internal residue, cracking or stiffness. Clean the end inside and out with the rag and some soapy water. The coolant should be clean with no rust, oil or cloudiness. If you intend to reuse coolant, strain it through some clean nylon hose to remove any loose debris or dirt.

Securely install the thermostat in the housing along with a new seal. A light smear of petroleum jelly will lubricate the seal and keep it from accidentally tearing while installing. Put a light coating of thread sealer on the capscrews and torque to 11 foot-pounds. Reconnect the upper radiator hose and seat the clamp. Make sure the drain cock is closed and refill the system with clean coolant. Start the car and bring it up to operating temperature with the heater on full. Check for leaks.

Items you will need

  • Pliers

  • Drain pan

  • Wrenches

  • Rags

  • Razor scraper

  • Cleaning solvent

 How to Change the Thermostat on a PT Cruiser

Pop the hood and locate the thermostat. It's on the passenger side of the engine and has a plug leading into it.

Unplug the thermostat housing from the engine block using the 3/8-inch ratchet and socket set. The housing will come off in your hand and then you can pull out the old thermostat.

Scrape off the engine block and the thermostat housing's mounting surfaces with the gasket scraper. This is to ensure the replacement gasket seals correctly.

Place the replacement thermostat into the engine block and place the gasket over the ends of the bolts in the thermostat housing to keep them aligned.

Bolt the thermostat housing into the engine block using the 3/8-inch ratchet and socket set.

Items you will need

  • 3/8-inch ratchet and socket set

  • Gasket scraper

  • Replacement thermostat

  • Replacement thermostat gasket

 How to Replace the Thermostat in a 95 Chrysler Cirrus LX

Replacing the Thermostat

We used the jacking points on the body molding behind the front wheels to jack and support the car. Both engines mount the thermostat inside the housing that also has the radiator cap. That makes it easy -- once I found the radiator cap, I found the thermostat housing. The thermostat in my 2.4-liter engine sat vertically inside the housing -- no surprise. On the other hand, the thermostat in my friend's 2.0-liter engine mounted horizontally inside the housing. On his engine, we had to make sure the vent on the thermostat was facing up when we installed it. I'd tightened the housing bolts on my engine to 110 inch-pounds, but on the 2.0-liter, we had to tightened them to 16 foot-pounds -- and be very careful not to over-tighten them lest we crack the housing. To refill the system, we used about a gallon and a half of ethylene glycol coolant mixed in a 50/50 solution. I found out later that technical service bulletin No. 07-03-97 issued in May 1997, stated that propylene glycol coolant is okay to use, too.

 How do I Replace a Thermostat in a '99 Chrysler 300M?

Drive the Chrysler 300M onto a set of ramps to raise the front of the vehicle off the ground. Raise it high enough so you can work under it comfortably.

Place a drain pan capable of holding four gallons of fluid under the lower radiator hose. Use a screwdriver to loosen the band clamp that secures the hose to the radiator, and then pull the hose off the radiator. Drain all of the fluid into the drain pan. This avoids loosening the petcock drain on the bottom of the radiator. Due to its age, it could be brittle.

Remove the other end of the hose from the water intake tube in the same manner as you removed it from the radiator. The intake tube holds the thermostat into the engine.

Remove the two bolts that secure the intake tube to the engine with an adjustable wrench. With the bolts removed, the intake tube, gasket and thermostat drop out of the engine. Catch them in your hand to prevent damage to the intake tube.

Remove the O-Ring, gasket and thermostat from the intake tube. Replace these older items with new ones.

Hold the intake tube against the engine and bolt it in place.

Inspect the old radiator hose for any cracks, dry rot or bubbles. If any exist, use a new hose. Slide the hose onto the water intake tube and secure it with the clamp. Place the other end of the hose back on the radiator and secure it with the clamp.

Open the radiator filler cap and drain the radiator fluid back into the radiator. If you use new fluid, use a 50/50 mix of radiator fluid and distilled water. Close the cap once filled.

Items you will need

  • Ramps

  • Four-gallon drain pan

  • Screwdriver

  • Adjustable wrench

  • Thermostat kit

  • Funnel

 How to Change the Thermostat on a 2000 Chrysler Concorde

Remove the top radiator hose from the thermostat cover by removing the band clamp that holds it onto the cover. Slide the clamp down the hose, then pull the hose off the cover.

Remove the 10mm bolts that hold the thermostat cover on the intake of the Concorde and pull the thermostat cover off the engine. Inspect the cover for any cracks around the housing and around the bolt hole tabs. If you notice any cracks, a new cover should be used.

Pull the old thermostat out of the intake manifold and install the new thermostat into the intake. The lip that the thermostat sits on will be below the level of the radiator fluid. The thermostat must be placed in properly to ensure it works correctly.

Pull the old thermostat gasket off the intake manifold and wipe down the surface with a towel to ensure it's clean before moving on. Place the new thermostat gasket into place. Make sure the hole on each side of the gasket lines up with the bolt holes for the thermostat cover.

Place the thermostat cover back onto the intake manifold and bolt it into place.

Slide the radiator hose back onto the thermostat cover and clamp it into place.

Items you will need

  • 2000 Chrysler Concorde thermostat

  • 2000 Chrysler Concorde thermostat gasket

  • Screwdriver

  • Towel

  • Wrench

 How to Change the Thermostat on a Sebring 2.7

Place the Sebring onto a set of ramps, secure the parking break and place a clean drain pan under the radiator petcock.

Open the petcock with a pair of pliers and drain two gallons of coolant from the radiator into the drain pan. Do not forget to close the petcock. Save the drained fluid to return to the radiator later.

Follow the upper radiator hose to the engine. The hose connects to the thermostat intake housing located on the engine. Remove the hose by prying the clamp off with a pair of pliers and then by pulling the hose off the housing.

Remove the two bolts that secure the thermostat intake housing to the engine with a socket and ratchet and lift the housing off the engine. If the housing sticks, use a small scraper to break the seal.

Take note of the thermostat's orientation in the engine, pull it out and place the new thermostat into the hole with the same orientation as the old one.

Scrape the old gasket off the bottom of the thermostat intake housing and then scrape the mating surface of the engine clean with the scraper.

Place the new gasket onto the mating surface of the engine. Place the intake housing onto the gasket. Thread the bolts through the housing with your fingers and then tighten the bolts with the socket and ratchet.

Slide the hose onto the Sebring's thermostat intake housing. Tighten the clamp into place with the pliers.

Open the radiator cap on the Chrysler's radiator and pour the two gallons of fluid back into the radiator.

Items you will need

  • Ramps

  • Drain pan

  • Pliers

  • Socket set

  • Replacement thermostat and gasket

  • Scraper

  • Funnel

 How to Change the Thermostat in a Chrysler Sebring

Raise the front of your Chrysler Sebring with a jack and jack stands or wheel ramps. Loosen the drain plug on the bottom of the radiator, located on the driver's side. Drain the coolant into a container. Reuse the coolant later if it is relatively new and clean.

Follow the upper radiator hose to an elbow where it turns into the front of the engine. This is the thermostat housing. Remove the hose from the housing. Remove the three bolts on the housing and pull off.

Note the position of the old thermostat before removal. Install the new thermostat in exactly the same position, with the spring-end facing the engine. Clean any debris and residue from the inside of the housing cover.

Install the new gasket over the thermostat. Reattach thermostat housing cover and radiator hose. Fill radiator with reserve or new coolant.

Start your Sebring. Turn on the heater and blow at the highest setting. Allow the engine to get warm. Check for leaks.

Items you will need

  • Jack and jack stands or wheel ramps

  • Container

  • Screwdriver

  • 10mm wrench or socket

  • Thermostat and gasket

About the Author

This article was written by the It Still Runs team, copy edited and fact checked through a multi-point auditing system, in efforts to ensure our readers only receive the best information. To submit your questions or ideas, or to simply learn more about It Still Runs, contact us.