Vehicles with the n52, n54 and n55 engines have common oil leak issues.
In Part 1 we will focus on the oil filter housing area leaks. Often times confused with oil filter o-ring leak, the filter housing which bolts onto the cylinder head has 2 major problematic gaskets. Oil filter stand gasket and oil cooler gasket. These gaskets over time get brittle, go bad and cause oil leaks. Oil cooler gasket failure could lead to oil contamination in the coolant system. If you see oil mixed into coolant in the expansion tank, this is a clear evidence to oil cooler gasket leak. Oil leak from the filter housing drops down the front right side of the engine block and contaminates critical components like pulleys and drive belts causing premature wears leading to failures.
Diagnostic is simple, repairs require removal of intake manifold. Below are the parts required to do this job properly (intake manifold gasket not shown). Coolant and motor oil also needed.