2000 cadillac deville laking water from the back of the engine where is it coming from?

Is it antifreeze or just water? If water, your AC system will frost up under use, which will melt and pool under the car on the passenger side (normal) after the engine stops. If antifreeze, there is a complicated cooling hose system, with some of them near the firewall. Check the overflow tank to see if you are losing coolant, and if so, check the hoses there while the engine is running.

Well there are a lot of things to look for and they are .
1st the engine would sound differant slight hissing or running a little rougher on idle or pick up.
2nd if head gasket is starting to blow between 2 cylinders then you will get a back firing through the exhaust or carby {depending on what cylinder is blowing to what cylinder} and if you are loosing water then you will see it in steam form coming out of the tail pipe of the exhaust and engine could be breathing steam back into A cylinder which would also make it run a bit rough.
BUT IF all the cylinders are running well and you are loosing water and cannot find the cause then it could be blowing out of the overflow tank on the side of the engine,and check on the thermostat as that can alsogive you the same problems.
So let me know how you get on
Ron.

hi. On a 4.9L follow the upper radiator back to the engine. This should be the thermostat housing. The thermostat should be inside.
On a 4.6L the thermostate is in the housing which is near the water pump drivebelts "on the coolant crossover housing". If this is not clean I recommend you buy the Haynes for your DeVille. See page 3-4, illustration 3.14.

Joe

FOR THE 4.6L ENGINE THE THERMOSTAT HOUSING LOCATION IS NEAR THE WATER PUMP DRIVE BELT ON TO COOLANT CROSSOVER HOUSING.

The thermostat could be bad. Run the engine cold with the cap off the bottle. If it comes out while the engine is still cold, you have a bad headgasket. Otherwise, start by replacing the thermostat.

need to have system checked to get trouble code

flush your radiator first.with the thermostat out you should see the water moving if not bad water pump.this engine needs the thermostat to function properly and either a 50/50 coolant or straight coolant so it does not boil over.also make sure your fans are coming on

on the drivers side of engine below the water pump drive belt the upper rad hose is attached to the housing that it is in

Sounds like an overheating problem, best to get it checked, maybe thermostat stuck closed, pluged radiator, head gasget, cracked head.

You can rent a cooling system preasure tester at a parts store. These engines run so close to boiling that they must be able to hold presure or they overheat. Presurize the system and check for even the smallest leaks at all hose connections. I fought this problem for a long time before I figured it out.