Engine Cooling problem
2000 Cadillac Deville 6 cyl Two Wheel Drive Automatic 90,000 miles
My car overheated along the highway. I broght it to the mecanic and after checking out the radiator, thermostat, and water pump he said it was the head gasket. I looked on line and none of the common observations re a head gasket were present e.G. White exhaust or the other usual signs. Another mecahic asked if they did a test for Co2 and that if I caould not get the car to him I could buy some type of tester that would measure if there was carbon dioxide in the radiator. Do you know what this is called. I went to a few auto supply companies and they didn't have it. I have read that you do not recommend sealants but a few people have used it with success?
What else are my options. A repair of the gasket is between $2,000 to $3,000 and to drop another used northstar engine in may also be problematic.
Hi machineface. Welcome to the forum. Expensive cars have expensive repairs but $3000.00 seems real high, even for a Cadillac. The typical cost for head gaskets for a V-type engine is a little over half of that. One test you can do yourself is to watch for bubbles in the overflow reservoir when the engine is running but still cold. If you see bubbles or it looks lile it is boiling, suspect the head gaskets. The clue is there will be no steam with the bubbles because the coolant is still cold.
The test they were referring to is what I call the " sniffer" test. It involves drawing air from the radiator through a glass tube with two chambers of dark blue liquid. If combustion gases are present, the liquid will turn bright yellow. The test strips are used to measure the acidity of the antifreeze. GM has a real lot of trouble with the red Dexcool antifreeze, (commonly referred to as " Dexmud" ), so most people don't test it; they just replace it. I've never seen test strips to check for combustion gases but that doesn't mean they don't exist. Most mechanics have the sniffer tester and it only takes a few minutes to perform the test.