Burping the cooling system?

2002 PONTIAC MONTANA
136,000 MILES • 3.4L • AUTOMATIC
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JAMES O BARBER
  • MEMBER
  • 1 POST
can my cooling system just by pulling out those two 8-in mipp plugs on top of the motor and letting some of that air out of there after warming the engine up thoroughly and running the heater of course. the heater won't throw heat right now and she gurgles when I shut her up. she needs a burping. I have a high quality cooling system pressure test slap it on and pump it up and then open the mip plugs again after warming the engine; so with it: so if it will be warm, it will be hot.
Sep 14, 2026 at 8:17 PM
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STEVE W.
  • ✓Experienced Mechanic
  • 15,359 POSTS
That engine has two air bleeders on it, one above the water pump and one on the thermostat housing. Generally you would start with the system empty, both bleeders open. Fill until you get coolant at the pump. Keep filling until you get coolant at the thermostat housing. Then you start the engine and let it warm up fully. Now you shut it off and let it cool down. Top up the coolant to the "full cold" level. Start the engine and let it get hot, let it cool again. If needed add more coolant until it hold the full cold level after it has sat cold.
Sep 15, 2026 at 11:11 AM
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