I have a 2007 Mazda 6 2.3 4cyl with a 5 speed automatic. i have always maintained my vehicles myself ( i have extensive knowledge of mechanics ). This week i smelled a bad burning smell coming from the engine area, and around the valve cover i saw small amounts of oil so i cleaned the area and replaced the valve cover gasket immediately. for one day i didnt smell oil and no leaks. today after driving to work and back i smell burning oil but see no leaks. I am assuming 1 of 2 things: either oil is leaking into the exhaust manifold, or somehow, oil is leaking intomy firing chamber and igniting. any one have a similiar problems? ( p.s. i have 118000 miles on it, all highway, besides brakes and oil changes and tires i havent had a problem with it ) would like some input. thanks

 

PCV valve. check the DIY threads.

 

On my 6 Wagon with the V6, the oil filter was ever so slightly loose causing a slow drip on the exhaust manifold. The oil never hit the ground, rather it burnt itself off on the manifold causing a little smoke, a lot of smell, and a couple of weeks of head scratching until I finally figured it out.