1989 GMC TRUCK
84,000 MILES
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DOUGDODGE1500
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I have a 89 chevy that keeps over heating. My coolant keeps dissapearing and i dont know where it is going. New thermostat and i have flusged the system. I am thinking head gasket but im not possitive. Any ideas?
Mar 19, 2013 at 2:07 AM
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JACOBANDNICKOLAS
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Have you checked to see if there is coolant mixing with the oil and the opposite?
Mar 19, 2013 at 2:25 AM
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CARADIODOC
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Much more common on the GM V-8 engines is a leaking intake manifold gasket.
Mar 19, 2013 at 2:25 AM
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DOUGDODGE1500
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The oil has no coolant in it i alrdy checked that. Im pretty sure its the intake gasket. But i dont wanna tear into it and have it be somthing else. I fill the system with coolant a nd it all disappears. It isnt leaking on the ground.
Mar 19, 2013 at 2:32 AM
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DOUGDODGE1500
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And is there any way to test to see if the gasket is bad?
Mar 19, 2013 at 2:34 AM
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CARADIODOC
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Pressure test may show it, but you can also add a small bottle of dark purple dye. The coolant may be evaporating as fast as it leaks out. After a few days, search with a black light. The dye will show up as a bright yellow stain that you can follow back to the source.
Mar 19, 2013 at 11:27 PM
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DOUGDODGE1500
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Okay well thanks. But am i right is it a head gasket? Cause thats what everyones telling me. Thats the only thing i can think of. Cus it doesnt leak on the ground cus u dnt see it in the snow. And plus some eater comes out of the exhaust when it is running
Mar 20, 2013 at 1:09 AM
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CARADIODOC
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Sure it could be a leaking head gasket but that would be a lot less common. You may be able to verify that with a chemical test at the radiator. With the engine running, air is drawn through a glass cylinder with two chambers partially-filled with a special dark blue liquid. If combustion gases are present that liquid will turn bright yellow.

If you think coolant is going out the tail pipe, the dye will show up there too.
Mar 20, 2013 at 3:39 AM
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DOUGDODGE1500
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Okay thank you for your help ill let you know what happens with it
Mar 20, 2013 at 2:20 PM