Question about 1996 Cadillac DeVille

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My car keeps running hot change water pump hoses temstat its in between fire and engine wall and somebody said its not heater core

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Firstly before commencing any new work , ensure that you do not have an air lock caused by replacing the previous various parts. Follow the pipe from the thermostat, with engine running and it should heat up when thermostat opens. Follow this pipe towards both the Heater matrix and the carburettor. Both should warm up slowly. Have the heating on inside the car to blow warm. Then feel the exit pipes from the Heater Matrix. The exit pipe should also heat up. If they remain cold the you have an blockage within the Matrix which can either be air or debris. To cure air, let car cool down and remove expansion vessel cap. Then remove exit pipe from heater matrix and hold pipe aas high as possible.....if air is causing the blockage then it will purge itself, when water starts coming out of Matrix, reconnect pipe and top up levels as required. If nothing comes out, the matrix is blocked, may respond to after market flushing treatments or may require removal (pig of a job) Do check before this that oil is not getting into water circuit (dark floating bits if mild, all light brown if bad)or vice a versa (white scum on bottom of dipstick)which would indicate blown head gasket is causing car to overheat!

Posted on Dec 08, 2010


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