How do you know if you have a blow head gasket on a Mazda protege?

Answer 1

Symptoms of a blown head gasket are, white smoke from the exhaust that has a sweet smell. Loss of coolant with no apparent leak. Bubbles coming from the radiator with the cap off. Coolant in the oil. Foamy looking substance on the underside of the oil cap. Over full of oil. Miss on any cylinder. A compression test will help determine if you do indeed have a blown head gasket. Stop driving this car until you know for sure. A blown head gasket can do serious damage to the engine in short order. A combustion leak detection kit will give you a fairly definitive answer. This kit includes a container that holds a chemical which reacts to the presence of hydrocarbons (exhaust gasses) in the radiator. The container is connected to a vacuum source, then placed over the radiator neck. Air from the radiator is drawn through the detection liquid, which turns color (yellow in this case) in the presence of exhaust gas. The only way exhaust gas is present in a radiator is if the head gasket is blown. Ergo, the liquid changes color, you're looking at a new head gasket at the very least. You can probably find the kit at an auto parts store; I found mine for about $30 USD at a tool store, but prices ranged upwards of about $45-$50 at the auto parts stores.