1999 Cadillac SLS Overheating

TWOBLAZE

MEMBER
1999 CADILLAC SLS
V8
FWD
AUTOMATIC
80,000 MILES

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.

4 Replies

DOCFIXIT

CERTIFIED MECHANIC
18,828 POSTS

Hi
Any coolant loss? Excessive white smoke from exhaust? Ckeck oil look normal or like chocolate malt?
Let me know
Thanks for donate

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Tuesday, February 17th, 2009 AT 11:30 AM

TWOBLAZE

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2 POSTS

No moisture in oil. No excessive moisture from exhust. The coolant level stays ok until the motor overheats and causes overflow. Thank you.

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Tuesday, February 17th, 2009 AT 2:43 PM

DOCFIXIT

CERTIFIED MECHANIC
18,828 POSTS

Assuming cooling fans working. Think exhaust gas superheating coolant. Have coolant checked for presence of CO. Let me know

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Tuesday, February 17th, 2009 AT 2:47 PM

FACTORYJACK

CERTIFIED MECHANIC
4,159 POSTS

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.

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Tuesday, February 17th, 2009 AT 9:49 PM