I have another STS and the other day i was looking under the hood, probably adding oil, i've been under the hood of this car every week for years, and i noticed the label that says to add two tablets into the cooling system every time the coolant is changed. So i stopp by the Caddy dealer and they say they don't have the part number thats on the label. So i go home look up the part number on RockAuto and low and behold its radiator stop leak. So this tells me that the dip****s at Cadillac knew of the head leaking problem when the engine was designed. What a ****ty deal. The dealership wanted to sell me these stop leak tablets, i just couldn't believe that Cadillac would do this to people, sell a car with a motor they knew would have issues with the heads and the cooling system.

That like buying the rope thats going to be used to hang you with. Now i'm on my forth STS, i'm just a stupid as stupid is.

I did get the oil consumption to be less than every other tank of gas. I used marvel Mystery Oil for a 300 mile trip back home. The motor must have gained 50 HP and oil consumption went to over two tanks of gas to once a month adding a quart. The motor had over 200,000 miles. My $0.02 .