1987 Pontiac Bonneville SEFACTORY OEM SERVICE PROCEDURE

Vacuum Control Temperature Sensor

  1. Tape a thermometer close to vacuum control temperature sensor located inside air cleaner. Leave wing nut(s) off top of air cleaner so that top can be quickly removed to read thermometer during test.
  2. With engine cold, temperature below vacuum control temperature sensor specifications, check air control door in air cleaner. It should be in fully open position (open to outside air).
  3. Start engine. As soon as engine starts, door should move to fully heated air position (closed to outside air). Continue running engine and watch air control door. When door reaches fully open position, quickly remove air cleaner top and read thermometer.
  4. Compare thermometer reading with specifications. If reading is not to specification, perform vacuum motor test. If vacuum motor is okay, replace sensor.
Factory Service Tools

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.

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