The vehicle leaks antifreeze near the rear of the engine on the driver's side?

1999 CADILLAC DEVILLE
125,000 MILES • 4.6L • V8 • 2WD • AUTOMATIC
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BROWNMATHTEACHER
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The leak does not occur until the vehicle has cooled down about forty-five to sixty minutes later. I go outside to look under the car and the leak is there on the cardboard which I replace regularly after driving. The leak saturates the cardboard and leaks onto the concrete. I normally must put one to two twelve ounces water bottles of antifreeze back in the antifreeze reservoir after the leak appears. A new water pump was placed on the vehicle with no success. There were no leaks once I replaced the antifreeze. The car does not overheat. A pressure test was conducted by the garage - twice. The mechanics are baffled. The engine temperature normally gets to about 213 degrees while driving around in the FT. Stewart, Ga area of 90 degrees running errands. There are no leaks when I stop at this store or that store to make purchases. I have been out as long as an hour at a time the last three weeks. The car drives beautifully. This car is well maintained. Can anyone help me or steer me in the right direction? Notr: How do I remove antifreeze stains from my driveway?
Sep 25, 2022 at 8:04 AM
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JACOBANDNICKOLAS
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Hi,

Has anyone used a leak detection dye in the system to locate the leak? The interesting thing about the leak is it happens when the engine cools off. When I think about it, steel expands when it gets hot and contracts when cold. As a result, I don't think it is a hose. Instead, I think it is something that is contracting when the engine cools. Has anyone checked for a head gasket leak or a leak at the intake manifold? Also, there are freeze/expansion plugs on the engine that also can leak. Can you do me a favor? Take a couple of pics of the approximate area where you feel the leak is coming from and upload them for me to see.

Take a look through this link as well to see if anything helps:

https://www.2carpros.com/articles/car-is-leaking-coolant

As far as the coolant on the driveway is concerned, the coolant won't evaporate. I would take hot water and a garden hose and simply try to rinse it away.
Sep 25, 2022 at 1:00 PM
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BROWNMATHTEACHER
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Thanks for your response. It was the heater hose(s). The shop called me early this morning with a response.
Sep 26, 2022 at 2:59 AM
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JACOBANDNICKOLAS
  • Experienced Mechanic
  • 110,240 POSTS
Hi,

Thank you for the update. I'm glad to know it was something simple. Interestingly, I wouldn't have considered a rubber hose leaking after it was cool. I was thinking it would have been worse when under pressure. LOL

Regardless, please feel free to come back anytime in the future. You are always welcome here.

Take care,

Joe
Sep 26, 2022 at 11:10 AM
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