How to Replace a Camry Thermostatby Chris Moore
The thermostat in your Toyota Camry can become stuck in either the open or closed position; either case will affect your engine's performance. A thermostat stuck open makes it harder for the engine to reach its optimum temperature, while a closed thermostat causes the engine to overheat. You need to replace the thermostat if it's stuck in either position. The exact replacement procedure can vary, depending largely on the type of engine the Camry has.
Disconnect the car's black negative battery cable by loosening its clamp nut with a wrench.
Drain the engine coolant from the radiator by placing a container under the radiator's drain plug. Remove the plug with the wrench.
Disconnect the radiator hose from either the thermostat housing or the water inlet pipe. Unbolt and remove the water inlet pipe. On a four-cylinder Camry engine, this is located between the alternator and exhaust manifold. On a V6 engine, the inlet pipe is bolted to the cylinder head with the thermostat housing at the back of the intake manifold.
Remove the nuts and electrical connectors for the thermostat housing and remove the housing; be prepared for coolant to spill out. Remove the thermostat from the housing, taking note of how it's installed within the housing.
Clean off both the thermostat housing and the engine surface. Use acetone or lacquer thinner and wait for it to dry.
Attach a new gasket onto the new thermostat; it will fit around the thermostat's edge like a ring.
Install the thermostat into the housing in the same direction that the old thermostat was in. Then install the housing in place on the engine and tighten its bolts/screws.
Re-install all the other parts and components in the reverse order of removal. On V6 engines, you'll need a new O-ring on the water inlet pipe; lubricate this O-ring with soapy water.
Refill the engine coolant, making sure the drain plug is re-installed and the heater control is at the maximum heat position. Use fresh coolant if the old coolant is dirty or contaminated in any way; use a 50/50 mixture of coolant and water.
Run the engine in a well-ventilated area with the radiator cap off until the thermostat opens; the coolant will start flowing and the upper radiator hose will get hot. Shut off the engine, wait for it to cool and more coolant mixture until it reaches the radiator filler neck lip.
Bleed air from the cooling system on a V6 engine by squeezing the upper radiator hose; wear gloves when you do this, as the hose will be hot. Add more coolant as needed.
- Check the engine coolant level. Test the drive belt tension and make sure the temperature gauge is operating properly before you conclude that the thermostat is the problem.
- The engine must be shut off for at least three hours before working on any part of the cooling system.