1994 grand prix overheating

1994 PONTIAC GRAND PRIX
187,000 MILES
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JAY DAVIS
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My 1994 Grand Prix recently overheated. I removed the thermostat and tested it in boiling water. It was bad, so I replaced it. Now the temp guage reads between 150-225 while driving and moves toward the red when stopped. When you accellerate, it comes back down. The water pump looked fine. Is the sensor the likely culprit, or is there something else I need to check?
Dec 28, 2011 at 6:03 PM
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DOCFIXIT
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Temp sensor may have been damaged located on rear of engine. Was coolant system air bleed?
Dec 28, 2011 at 6:12 PM
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JAY DAVIS
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I bled the air according to the procedure in the Haynes manual. When I first started it, there was still air trapped in the heater core though, I could hear it gurgle.
Dec 28, 2011 at 6:56 PM
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DOCFIXIT
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so opened bleeder valve till only coolant came out?
Dec 28, 2011 at 6:59 PM
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JAY DAVIS
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That is right.
Dec 28, 2011 at 7:01 PM
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DOCFIXIT
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can Ohm check temp sender @1k cold droping to @80 at 220. What temp is cooling fan coming on?
Dec 28, 2011 at 7:09 PM
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JAY DAVIS
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I am not sure. Will have to check that.
Dec 28, 2011 at 7:19 PM
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DOCFIXIT
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Maybe fan issue to check if it will operate turn AC on fan should come on to prove its operational
Dec 28, 2011 at 7:23 PM
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JAY DAVIS
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To Ohm check the temp sensor, do i check resistance between the two terminals?
Dec 28, 2011 at 7:27 PM
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DOCFIXIT
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yes connector off
Dec 28, 2011 at 9:29 PM
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