It is not uncommon for the intake manifold and/or valve cover gaskets to develop a coolant or oil leak. Leakage from the intake manifold may result in coolant in the engine oil. Coolant mixing with the engine oil severally impacts the lubrication ability of the oil. Internal engine may result if this condition is not repaired promptly.
Car Problem Reports
Ford Mustang Intake Manifold/Valve Cover Gaskets May Leak Oil
Ford Mustang Problem
Engine Affected: 2.3L 4 Cylinder
Average Mileage: 141,666 mi (75,000 mi - 180,000 mi)