* Oil cooler gasket leak: The oil cooler gasket is a seal that prevents oil from leaking from the oil cooler. If this gasket fails, oil can leak onto the radiator.
* Oil filter housing gasket leak: The oil filter housing gasket is a seal that prevents oil from leaking from the oil filter housing. If this gasket fails, oil can leak onto the radiator.
* Valve cover gasket leak: The valve cover gasket is a seal that prevents oil from leaking from the valve cover. If this gasket fails, oil can leak onto the radiator.
* Cylinder head gasket leak: The cylinder head gasket is a seal that prevents oil and coolant from mixing. If this gasket fails, oil can leak into the coolant system and eventually end up on the radiator.
If you find oil on the radiator of your BMW, it is important to have it inspected by a qualified mechanic to determine the source of the leak and have it repaired as soon as possible.
