2002 Mazda 626 Q&A
2002 Mazda 626 Question: what are the most common oil leaks in this engine?
Valve cover gaskets, cam and crank seals, rear crankshaft oil seal. Oil leaks can be caused by excess crankcase blow bye or a bad PCV valve. Check the crankcase is breathing properly and not building up pressure. After that perhaps you would need to add dye to the oil and look at it with a florescent light to pinpoint the source of the leak. - patrick mannion