99 Cadillac Deville

1999 CADILLAC DEVILLE
15,000 MILES • V8 • AUTOMATIC
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JUNEBRII
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  • 2 POSTS
My 99 cadillac deville has been overheating. I have replaced the thermostat, bottom radiator hose, and still have to add water daily. There is no visible leak but everytime i check the water it is low and i have to add more each time i drive. What is my problem and how can i fix it?
May 3, 2011 at 9:31 PM
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CARADIODOC
  • ✓Experienced Mechanic
  • 34,367 POSTS
Sounds like you might have a leaking head gasket although that isn't real common on your car. There are three different tests that can be performed. One is a pressure test that puts the system into 15 pounds of pressure, then you search for the source of the leak. The second one is to add a small bottle of dye to the coolant, then you search with a black light. The leak will show up as a bright yellow stain that you can follow to the source of the leak. The third test involves drawing air from the radiator through a glass cylinder with two chambers partially filled with a special dark blue liquid. If combustion gases are present from a leaking head gasket, the liquid will turn bright yellow.
May 3, 2011 at 10:06 PM
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CADIEMAN
  • ✓Experienced Mechanic
  • 3,544 POSTS
you will need to check the a/c case drain. its right below the evaporator for signs of coolant.heatercore may be leaking.gl
May 4, 2011 at 9:59 AM
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