1998 Cadillac Deville Loosing water

1998 CADILLAC DEVILLE
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GRAMPA
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Engine Cooling problem
1998 Cadillac Deville V8

I replaced my thermostat and the car stopped overheating, bt now it seems like the water is some how evaporating, I have to put water everyday, but I don't see a puddle under the car, I did have white smoke come from under the hood a couple of days ago, can you tell what the problem might b? Thanks
Jan 18, 2009 at 11:59 PM
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DOCFIXIT
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Pull oil dip stick look normal? or like chocolate malt?
Aug 18, 2019 at 10:05 AM
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GRAMPA
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The dip stick looks normal, I just had the oil changed yesterday
Aug 18, 2019 at 10:05 AM
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DOCFIXIT
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Have system pressure checked and new cap if cap cannot hold 15 psi then coolant will boil and evaporate at normal engine temp
Aug 18, 2019 at 10:05 AM
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GRAMPA
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Yes Hello, I asked you about why my 1998 Cadillac DeVille the water seems to be evaporting, and you told me to buy a new radiator cap, I went to the Cadillac dealer and bought one, but its doing the same thing, I check under the car, the water dosen't seem to be coming out there, there is no water in the oil, can you tell me what else I can do? Thanks so much again, Robert Reyes

The car runs excellent, I just hate having to put water in it everyday
Aug 18, 2019 at 10:05 AM
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DOCFIXIT
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Any white vapor from tailpipe especially at start up in A.M.?
Aug 18, 2019 at 10:05 AM
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GRAMPA
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No I haven't seen any white smoke
Aug 18, 2019 at 10:05 AM
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FACTORYJACK
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At what rate are you adding fluid(qty/time). As stated in earlier post, have the system pressure tested, preferably cold, and block tested for combustion gases in the cooling system. Anything over 3 PPM hydrocarbons indicates a problem. I would take a guess you have a water pump housing(crossover) leak, or a leaking head gasket due to pulled head bolt threads in the block.
Aug 18, 2019 at 10:05 AM
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GRAMPA
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what I don't understand is where is the water going? I fill it with water every other day,in the morning. the radiator seems to be empty because it takes a lot of water to fill it back up.
Aug 18, 2019 at 10:05 AM
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FACTORYJACK
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If your not seeing it on the ground(i.e. external leak), then I would say the engine is processing it. It could be at an amount across 1 or 2 cylinders or more, that you won't even notice steam at the tailpipe. How does it start after sitting overnight, does it run a little rough for a few seconds? If so, that is an indication that the difference in pressure is allowing some water into a cylinder. As you shut it down after warm, there is cooling system pressure still present. This will push the water past a leaking head gasket into the cylinder, since the compression pressure is not there to keep it back. And as the engine cools, and metals contract, the ability for this to happen increases. As it runs, there is still water being drawn in as well. A cold engine pressure test, and a block test from a cold start, if possible, should produce some results. If you have an external leak, it should be noticeable at the rate you are describing. You also mentioned overheat, this could make an internal leak even more possible.
Aug 18, 2019 at 10:05 AM
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