Question about 1999 Cadillac DeVille

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I have a 1999 cadillac deville i bought a new water pump new t-stat and it still over heast it goes up takes about 20 to 25 min to get up to 230 .i took out the t-stat so the water can always flow trough but thats not the problem the water flows just fine its just the water gets hot.

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The radiator cap may not be holding enough pressure. Also, don't drive without the thermostat. It will mess up the closed-loop operation of the fuel injection system. That trick worked 40 years ago.

Posted on Aug 24, 2011


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Oct 10, 2012 | 1999 Cadillac DeVille

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My 2001 cadillac deville is overheating the first time it done my water pump tensner pulley wheel broke why did that happen could my water pump have frozen up or something. i had a pressure test done on it...

either the bearing in the water pump froze up, or the bearing in the tensioner froze, this can also cause the serpentine belt to be thrown off of the pulleys.

Apr 18, 2011 | 2001 Cadillac DeVille

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I bought a thermostat from advance auto parts for my 1999 cadillac deville but I was told that it should only be bought from a cadillac dealership but I used it anyway. I put the thermostat on and the car...

Who did all this work?
Was the water pump bad?
Was the radiator, so clogged it could not be cleaned?

What diagnostics was done?

Is the car actually over heating? That is where you start

All that work may have been for not

When you removed the stat,the temp never went up,only the gauge,
can not run a veh without the stat, the temp sensor needs it in there

Is the exhaust converter partially blocked?
Is the engine running rich

Have the data looked at.

Nov 24, 2010 | 1999 Cadillac DeVille

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Replacing the thermostat on a cadillac deville

Assuming you have the Northstar engine....

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Remove the hose from the housing,then remove the two bolts on the flange,the thermostat can then be pulled out.
Take note of the orientation of the thermostat as you remove it.
Don't forget the new gasket when you install your new stat.

Jan 12, 2010 | 1995 Cadillac DeVille

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Thermostat location on a 1999 cadillac deville concours

looked it up online and looks like it's on the front of the water pump in a thing called the coolant inlet housing. one end of it looks something like the letter y and the other end, where the thermostat is round. hope that helps

May 30, 2009 | 2000 Cadillac DeVille

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99 Cadillac Deville Coolant Leak

Most likely a cracked block or free plug that came out or loose. Other options are hozes, which I believe the dealer would have fixed. A third option is the water pump itself. 

May 06, 2009 | 1999 Cadillac DeVille

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Special tool to remove water pump on 1999 cadillac deville

remove air filter housing,remove secondary air check valve bracket,if equipped,remove lower radiator hose from the thermostat housing,remove waterpump bypass hose, remove waterpump cover,use special tool to remove waterpump,install a new o-ring inwaterpump housing

Apr 10, 2009 | 1999 Cadillac DeVille

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