Two things you should look into... either there is a PCV fault or bad injector lower O-rings. The PCV (positive crank ventilation) system is designed to allow the engine crankcase to breathe. It takes crankcase fumes and returns them to the intake manifold. The PCV valve is in place to not allow the revere of this flow to happen. In other words, the valve is supposed to stop intake manifold air/fuel mixture to flow to the crankcase, and only allow crankcase fumes to floe to the manifold. A defective PCV valve (easy to replace and inexpensive part) will let air/fuel mixture to seep past the valve and into the crankcase and ultimately, oil pan. The second fault can be defective lower fuel injector rings. The lower rings are supposed to separate the engine cylinders from the injectors and injector fuel rail; only allowing fuel to enter the cylinder directly and not to any oil passages. Replacing the O-rings is costlier than replacing the PCV valve. We recommend inspecting the PCV system first.
posted by SmogTips Support