Two problems related to engine burning oil have been reported for the 2004 Toyota Matrix. The most recently reported issues are listed below.
The engine burns excessive amounts of oil and has now starting making what appears to be either faulty lifter or camshaft noises. The Matrix burns at least 1 quart of oil for every 1000 miles driven. I do regular maintenance and monitor the oil level weekly.
The engine had "sludged" at about 70,000 miles (2004 Toyota Matrix). The Toyota dealership had done the oil changes routinely since I purchased the car certified. The engine was rebuilt using an extended warranty I had purchased from a private company (not Toyota). The car was knocking when I was driving home from michigan to florida. I checked the oil, it was dry, so I bought more oil and filled it (2 quarts). By the time I got home, the oil stick again read empty, so I again filled it. I did not see any oil burning (the smoke cloud). Another day passed and the oil was empty again, so I took it into the shop and they determined the oil had been clogged.