As I was driving, a burning smell emanated from the car. There were no check engine lights on. When I pulled over, I saw a lot of smoke coming from the engine. I checked the oil level and it was above the minimum line bit just barely, even though my husband had just done an oil change on it. I refilled the oil and continued on my trip. The problem repeated for several dqays until I got home and took it to the Mazda dealership. They reported the following: ‘Cylinder Head Assembly: oil leaking out of back of head, recommend replacing cylinder head and related gaskets. The cylinder head sits above the cylinders on top of the cylinder block. It closes in the top of the cylinder, forming the combustion chamber. This joint is sealed by a head gasket. In most engines, the head also provides space for the passages that feed air and fuel to the cylinder, and that allow the exhaust to escape.’ This service is $5600! My car only has 80K miles on it. This is a safety issue because there was no warning. No check engine light appeared and there was no warning.