My 2005 Cadillac CTS V6 3.6L began overheating last monday march 29th, 2011 out of the blue with the warning message "Engine Hot - AC Off". I glanced at the temp. gauge and noticed the indicator hit the red zone. I let the car cool down and eventually open up the cap off the bubbling radiator reservoir. Took it to Meineke the next day and they say radiator (which I don't believe) and thermostat. Took it to a repair shop and they say thermostat and/or water pump. Another two repair shop say head gasket MAYBE. Radiator replaced new 22 months ago, new thermostat 18 months ago, and new water pump 16 months ago. From cold start the engine heats up to midpoint temperature in like 5 minutes after driving, then after another 3 minutes the fan comes on and the engine starts to go from midpoint region to red zone of temperature gauge. So the temperature can go from low to red zone in about 12 minutes from a cold start. When idling, temperature seems to remain stable. I get regular oil changes with synthetic oil and drive this car very smoothly and easily at all times. Although, a day or two before this problem the "Check Engine Oil Low" light came on even though my car had 19% Engine Oil life left. Please anyone let me know what these symptoms indicate. Whether thermostat, water pump, radiator, and/or head gasket. I have visited www.seal-a-head.com and their product Dura-Seal seems like a sure fire solution to my head gasket issue.

 

i am betting head gasket it going or gone. and those sealer are ok for a "get you by" fix, but by no means should you drive for a prolonged time on that. the sealent will fail down the road (especially if you live in a hot climate). and then if you get to the point where the sealent is going, you might warp the block. then that will be one nasty repair bill.