How to Replace the Thermostat on Kia Cars

by Contributing Writer

Most of us welcome the opportunity to save significant money by tending to some basic and intermediate car care on our own. Replacing a thermostat can be challenging, but you can be successful if you plan properly and take your time with each step. If your car shows signs of overheating when stopped but cools down when in motion, it may be a sign that your thermostat needs to be replaced.

Under The Hood:

 How to Replace the Thermostat on a KIA Rio

Park your Rio on level ground and engage the parking brake. Let the engine cool for at least 30 minutes before beginning procedure.

Place the drain pan under the vehicle and completely drain the cooling system. The Kia Rio's coolant drain plug is located on the bottom side of the radiator. Some year models may require you to remove a plastic engine brush guard from below. These guards can be removed with a socket wrench. Set the coolant in a safe place while you are changing the thermostat--keep it away from children and animals because its sweet smell and taste attracts them and can be deadly.

Use the pliers to remove the clamp from the upper radiator hose connecting to the thermostat cover, located on the passenger side of the Kia Rio engine bay. Cover the opening of the hose to prevent contaminants from entering your cooling lines.

Remove the bolt from the thermostat cover, then set the cover aside. Remove the gasket and the thermostat. Thoroughly clean the opening where the thermostat was mounted; discard the gasket, it cannot be reused.

Place the new thermostat in its place and then attach the new gasket and the thermostat cover. There is one bolt that mounts all three of these parts; tighten this bolt to 14 to 19 foot-pounds with the torque wrench. Replace the upper radiator hose.

Inspect the coolant you drained from the vehicle. If it is dirty or contaminated, replace it with new coolant. Otherwise, refill the coolant from the coolant reservoir (removing the radiator cap is not recommended). If you are replacing the coolant, check with your local waste authority for proper coolant disposal. Engine coolant is toxic; it can harm animals and humans and pollute water.

Items you will need

  • Pliers

  • Drain pan

  • Socket wrench set

  • Torque wrench

  • Replacement thermostat

  • Replacement thermostat gasket

  • Hand towel

  • Replacement coolant (optional)

 How to Replace a Thermostat in a 2001 Kia Sportage

Park the vehicle on a level surface. Allow the engine to cool.

Take off the radiator cap. Place the catch pan under the drain cock on the bottom of the radiator. Open the drain cock until coolant flows freely out of the radiator. Drain the radiator until the coolant level in the radiator is below the level of the thermostat housing. Close the radiator drain cock.

Trace the upper radiator hose back to the engine to locate the thermostat housing. Place the drip pan on the ground under the housing to catch any accidental coolant spills. Unscrew the two retaining nuts on the thermostat cover. Remove the cover from the thermostat housing. Remove the gasket. If the gasket is stuck, carefully scrape the gasket off the metal. Do not let parts of the gasket fall into the thermostat housing.

Examine the existing thermostat and note the direction it is facing. Remove the used thermostat. Install the new thermostat, making sure it is facing in the proper direction and that it is properly seated in the housing.

Install a new gasket. Align the gasket with the openings for the thermostat and the two retaining studs for the thermostat housing cover. Replace the thermostat housing cover, and secure it with the retaining nuts. Do not overtighten the housing retaining nuts, because that could cause damage to the gasket.

Refill the radiator with a mixture of half automotive antifreeze and half water. This provides optimum engine cooling while preventing boiling of the coolant fluid.

Test the new thermostat operation by starting the engine and allowing it to warm up with the radiator cap removed. As the engine approaches normal operating temperature, the thermostat should open and coolant flow should be visible in the radiator. Replace the radiator cap as soon as the coolant flow is visible. Allow the engine to warm to normal operating temperature. Check the thermostat housing for fluid leaks. Make sure the engine cooling fan located behind the radiator turns on and off as it should. Be sure the temperature gauge on the driver's instrument panel indicates a normal engine temperature.

Items you will need

  • Wrenches

  • Screwdrivers

  • Drip pan

  • Automotive antifreeze

  • New thermostat and gasket

 How to Change the Thermostat on a KIA Sedona

Drain the coolant from your radiator. Use a socket wrench to remove the drain plug from the bottom of your radiator, if necessary. You also have the option of disconnecting the lower radiator hose from the unit. Use the appropriate screwdriver to loosen the O-clamp and pull off the hose. Make sure to use a drain pan to catch all of the antifreeze as it drains from the radiator.

Remove the engine cover. On the Kia Sedona, it's the large, gray composite piece that sits right in the top center of the motor. Use the appropriate screwdriver (such as a Phillips) to remove the six screws that hold the cover.

Take off the air intake. There are two Phillips head screws that hold the air intake in place. It's very quick to remove, and is located just to the right-center of the motor.

Move the air filter box. There are three Phillips head screws that hold the air box in place. It is also quite easy to remove. At the rear of the air box is a skinny hose that you need to remove in order to pull the entire assembly from the engine compartment.

Remove the radiator hose by loosening the O-clamp that holds it on to the radiator. Removing the radiator hose gives you a little more hand room so that you aren't busting your knuckles on all of the engine parts.

Take off the thermostat housing. This has three bolts and takes a bit of patience and work to complete. Two of the bolts are tough to move. The easy one should be the one you'll see and is closest to your position. The second one requires you to gently push some wiring aside to fit your hand in place. The third one on the back side of the housing is the one you have to feel for and remove without seeing it. Keep in mind, you'll have to replace it in the same way.

Remove the malfunctioning thermostat. It won't be easy to do with your fingers, so I recommend you do this with a pair of needle nose pliers. The thermostat may be held in place because of vacuum, and the pliers give you the necessary leverage to twist it a bit to pull it loose.

Replace the old unit with your new thermostat and gasket. Once installation is complete, put all of the engine parts you've removed back in place by reversing the steps above. As with most do-it-yourself auto tasks, you will likely find that putting everything back the way it was is much faster than breaking it all down for the repair. Remember to fill your radiator with the proper level of coolant per the manufacturer's recommendations.

Items you will need

  • Socket wrench

  • Drain pan

  • Phillips screwdriver

  • Standard screwdriver

  • Needle nose pliers

  • New thermostat

 How to Change the Thermostat in a Kia Spectra

Pull the negative ground cable from the battery. Drain the engine coolant so that the level is below the thermostat. Store the coolant in a suitable container and recycle it.

Take out the water inlet fitting, the gasket and the thermostat. Discard the gasket Clean all the gasket mating surfaces thoroughly to remove all old gasket material, dirt and debris.

Position the thermostat in the housing so that the jiggle valve facing up. Install a new gasket on the thermostat.

Connect the water inlet fitting. Torque the bolts to 14 to 19 foot pounds on the 1.5L, 1.6L and 1.8L engines. Torque the bolts to 11 to 15 foot pounds on the 2.0L engines.

Use the appropriate type and mix of coolant to refill the engine. Reconnect the negative battery cable.

Start the engine. Test for leaks. Recheck the coolant level and add coolant as needed.

Items you will need

  • Mechanic's toolset, including a full socket set, wrenches and screwdrivers

  • Replacement thermostat, new or rebuilt

  • New gasket for thermostat

 How to Change the Thermostat in a 2001 Kia Rio

Removing and Installing Thermostat and Gasket

On my 2001 Kia Rio, the drain cock is on the bottom, driver side of the radiator. I found my car's thermostat housing by following the upper radiator hose from toward the engine; the metal component connecting the hose to the engine is the thermostat housing. When I reinstalled the thermostat, I positioned the jiggle valve -- the loose-fitting valve on the thermostat -- in the 12 o'clock position. I torqued the thermostat housing bolts to between 14 and 19 foot-pounds. I finished everything up by refilling my Rio's radiator to the base of the filler neck with 50-50 premixed, ethylene glycol-base -- green -- coolant. After refilling it, I burped the cooling system by idling the car with the radiator cap off and topping off the radiator each time the coolant level dropped. Once the level was steady, I installed the radiator cap, allowed the engine to cool and rechecked the coolant level in the radiator and the radiator reservoir -- I needed to top off the radiator and fill the reservoir to the "Max" line after the engine cooled down.