Temperature Sensor Replacement; Thermostat Replacement - Chevrolet Impala SS Handbook

Tools:
There are two different sensors. There is one on the water pump which sends readings to the PCM, and
there is one in the passenger's side manifold that sends reading to you gauge on the dash.
Both sensors can be unscrewed with a crescent wrench but it is recommended that you use a deep socket.
Both of these sensors may also be replaced at the same time as the water pump is without the need to worry
about coolant leaking.
Water Pump Sensor
The water pump sensor is simple to replace. Simply unscrew the sensor from the water pump after
disconnecting the electrical connector. Have the new one ready with Teflon tape on the threads and install it
when the old one is removed. Coolant will leak so have some rags or bucket handy to catch any leaking
coolant.
Manifold Sensor
This one is more difficult and the most common cause of gauge problems. Raise the vehicle, and feel
around the middle of the engine around the headers. Do this when the car is cool. The sensor will be covered
in a heat resistant silver coating to repel heat. Pull back the wrapping and disconnect the sensor harness.
Slowly unscrew the sensor until loose enough to finish it by hand. Coolant will come out of this hole pretty
fast so you will need to be quick and do not have your face looking directly up at the sensor or you will regret
it. Once you get the sensor out, quickly install the new one, wipe off any excess coolant and reconnect the
sensor.
Tools:
Procedure:
1. Remove Home Plate and First Base. See Home Plate Removal and First Base Removal for more detail.
Once you have everything off, you will see the gooseneck coming out of the water pump. Your thermostat
is underneath that neck.
2. Release the petcock at the bottom of the radiator on the driver's side to lower the level of coolant to
prevent a lot of spillage. Not too much, just a little will do.
3. Now remove the hose clamp from the upper radiator hose leading into the water pump (you will need
pliers for the original clamp). Before you remove the hose, have some rags and/or a bucket to contain the
spillage.
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Maintenance: Cooling System
Temperature SSensor Replacement

Thermostat Replacement

SSHandbook