This is my 2007 Mazda CX7 with a 2.3l 4 cylinder direct injection turbo engine with 11,000 miles. I pulled off the intercooler to clean some things and this is what I find. The speculation is PCV system and maybe an oil catch can would help... but I can't help but think why a manufacturer would think this is an acceptable engine design? There is a puddle of oil/contaminants in my intake right before the throttle body lol. Cold side of intercooler After intercooler, right before throttle body.