Cadillac Repair/Overheating


Can you tell me how I can tell if I have a blown head gasket or cracked head in my 99 deville northstar? I do not see any signs of water in the oil, no visable leaks or puddles of coolant, but I do not see any movement in the throat of the overflow tank, could this be a water pump issue? and my radiator is new but am wondering if my new thermostat may need to be a summer not winter.  Tank you


The thermostat is almost never the problem.
Have the cooling system pressure checked. Make sure the fans are running.
Blown head gaskets will also show with white smoke coming out of tail pipe(s) warm engine.

If you eliminated any leaks from a pressure test and don't have white smoke, you may have a circulation problem in cooling system. I recommend a power flush.
These aluminum engines melt if temp gauge goes above 225 degrees. Hot lite comes on no matter where you are, must be shut off!

Good luck.

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Rob Painter


Alarm system questions cannot be answered on this forum. These systems are not what I can answer. Without being physically at the vehicle and not knowing what kind of electrical service has been done on the vehicle, there is no possible way to give an accurate answer over the internet. My expertise is in Ignition/key based anti-theft systems. These issues include GM VATS (resistor chip in key blade) PASSLOCK (MRD)-ignition lock rotation based, no special ignition key and the PKIII Transponder (computer chip in key) systems. These systems are not alarm based and are integral with the starting of the engine. This is why I cannot diagnose alarm problems without physically looking at the vehicle: Alarm systems are a completely different annimal than ignition key/lock based anti-theft system. Many alarm questions come from vehicles 10 years old, and since older, many hands that had been involved over the years.I am an expert in all GM factory (ignition/key based)systems. Alarm system questions pose to many situations beyond my knowledge as to what has been done to the vehicle over the years. Some guy may have actually wired the stereo into the alarm system. Who knows? Over my past 30 years in vehicle wiring repair, I have seen unbelievable wiring disaters done by guys that consider themselves "mechanics." I have seen stereos and alarms intalled using surgical tape. I have seen modules burn up, un-fused circuits, wiring jambed between the doors and even lamp cord used for a starter kill. To answer alarm questions over the internet without examining the vehicle is like asking; What does it take to remove a dent?


Education/Credentials-ASE certified. 11 years with a GM dealer and 17 years with a repair facility dealing with only the repair of theft recovered vehicles.

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