1999 Cadillac SLS Overheating

1999 CADILLAC SLS
80,000 MILES • V8 • FWD • AUTOMATIC
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TWOBLAZE
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1999 SLS overheating. Starts and runs fine. Short highway drive or hard on gas pedal and car will overheat. Replaced thermostat - did not flush system - no change. Live in MN = cold - hard to flush right now, raidator is getting cold air. Car blows cold air when it overheats.
Feb 17, 2009 at 8:38 AM
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DOCFIXIT
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Hi
Any coolant loss? Excessive white smoke from exhaust? Ckeck oil look normal or like chocolate malt?
Let me know
Thanks for donate
Feb 17, 2009 at 11:30 AM
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TWOBLAZE
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No moisture in oil. No excessive moisture from exhust. The coolant level stays ok until the motor overheats and causes overflow. Thank you.
Feb 17, 2009 at 2:43 PM
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DOCFIXIT
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Assuming cooling fans working. Think exhaust gas superheating coolant. Have coolant checked for presence of CO. let me know
Feb 17, 2009 at 2:47 PM
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FACTORYJACK
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Did you install thermostat, and if so, was the air bleed at the top. My initial thought is you have an air pocket, or you have a stuck closed thermostat. It would be advised to check for combustion gases in cooling system as previously stated.
Feb 17, 2009 at 9:49 PM
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