Nissan Altima vehicles with the 3.5L V6 engine can experience oil leaks from the engine due to a leaking oil cooler o-ring. This leak often occurs after an oil change because the oil filter is attached to the cooler and removing and installing the oil filter can alter the oil cooler o-ring sealing capabilities.

Repairing the leak requires removing the oil filter and the oil cooler and replacing the 0-ring. In some cases, it's recommended you replace the oil cooler but if this is suggested, be sure to get validation from the mechanic as to why they aren't replacing just the o-ring.

In severe cases where the oil has been leaking for a considerable amount of time and the oil level drops very low, owners have reported noise from the engine due to low oil pressure and/or a check engine light on with an OBD-II Code P0011 DTC set.