I got word from a friend who works at a dealership that 2 TB's came in recently with seized engines where the oil pressure switch/sensor rotted out and the engine lost oil. Decided that this oil change would be a good time to change out the oil sensor.
2005 Trailblazer, 4.2 I-6
Location of sensor:
2" above the oil filter.
1 1/16" 6 pointed deepwell socket. Note: the oil sending unit/switch specialty socket that "fits most sensors" from Advanced and Autozone did not fit the sensor i had.
~5 Minutes if coordinated with oil change.
Level of difficulty:
If you can change your oil, you can do this.
With the oil filter removed, and accessing the sensor from underneath, unclip the wire connected to to the sensor. I was able to squeeze a 1/2" ratchet and the 1 1/16" socket onto the sensor to break it loose and then unscrew by hand. Screw in the new sensor and connect the wire. Done.
- as stated above the specialty socket for oil pressure sensors that fit 1" up to 1 1/16" did not fit this sensor.
- The sensor that came up in the computer for the 05 trailblazer was incorrect from Advanced Auto. I had to go back and return the sensor after removing the existing sensor and realized they were not the same. The correct sensor was for a 2003 TB in their system after comparing the sensor i brought in.
- Nothing had to be disconnected and removed if you access the sensor from underneath as you would change the oil + filter.