Why is car coolant pouring out of the overflow tube?

Asked by D. Apr 11, 2018 at 06:51 PM about the 1999 Cadillac DeVille Sedan FWD

Question type: Maintenance & Repair

I have a 1999 Cadillac Deville.  Two weeks ago, the car was losing coolant
on the passenger side towards the front of the car.  It was on the radiator
and the air deflector.  The mechanic said it was the radiator.  It was replaced.  
Today, the car overheated, and the coolant was boiling and coming out of the
overflow tube on the coolant reservoir cap straight to the ground.  I was told
that with the northstar engine, it was likely the head gasket.  Is that the only
possible culprit?

2 Answers

103,215

The best way to determine if head gaskets are involved is to give your engine a compression test. It's a fairly cheap an easy test, you can even buy the apparatus and test it yourself, just have to remove spark plugs. If any cylinder measures 10% less than other cylinders, it's likely the head gasket has blown. A blown head gasket can over-pressurize a cooling system, forcing coolant out as you're seeing.

3 people found this helpful.
30

my Cadillac is overheating and is coming out of overflow jug could you tell me what's wrong with it I put the thermostat I got the radiator change is anything else you can tell me

3 people found this helpful.

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