How to Put a Thermostat in a 1999 Hyundai Elantra

The Hyundai Elantra is a compact passenger car that has been available in the U.S. since 1992. With the 1999 model, Hyundai introduced a 2.0-liter engine that remained largely unchanged until the Elantra was redesigned for 2007. As with all engines, the cooling system plays a vital role, and a properly operating thermostat is central to that system. It's important to replace a faulty thermostat as soon as possible. Fortunately, this is a simple task that Elantra owners can easily do themselves.

Instructions

1

Park the Elantra on a level surface and allow the engine to cool for at least 30 minutes. Open the hood and carefully test the radiator to be sure it is not hot.

2

Remove the radiator cap. Slide under the front of the vehicle and locate the drain plug on the bottom of the radiator. Place the drain pan under the plug. Loosen the plug with a pliers until coolant flows freely out of the radiator. Allow the radiator to drain until the coolant level in the radiator is below the level of the thermostat housing. This will be when the radiator is about half empty. Close the drain plug with the pliers.

3

Locate the thermostat housing by following the bottom radiator hose back to the engine. Place the drain pan under the thermostat housing to catch any coolant drips. Undo the two retaining bolts on the coolant outlet fitting. Remove the fitting from the thermostat housing.

4

Remove the gasket that was forming the seal between the coolant outlet fitting and the thermostat housing. If the gasket is stuck to the fitting or the housing, gently scrape the gasket off the metal. Take care not to scratch the metal surfaces.

5

Pull the thermostat straight out of the thermostat housing. Insert a new thermostat so that the thermostat flange seats properly in the housing.

6

Install a new gasket. Reinstall the coolant outlet fitting.

7

Refill the radiator with coolant. If the coolant that you drained is clean, reuse it. Otherwise, use a mixture of equal parts of engine antifreeze and distilled water.

8

Start the engine. Observe closely for coolant leaks as the engine warms up. The thermostat should open at the specified temperature of 177 degrees F, and it should be fully open at the specified temperature of 201 degrees F. Be sure the engine temperature reading on the driver's instrument panel is normal, and that the cooling fan cycles on and off as it should. Close the hood.