Some customers may complain of an engine oil leak that appeared as they were driving the vehicle in extremely cold ambient temperatures (Generally 0 F /-17 C or Colder). They may also comment that they heard a single "pop" noise right before the oil leak started. Upon inspection, the technician will find that the oil leak is coming from the rear main oil seal of the engine as shown below. This may be the result of a frozen PCV system and excessive crankcase pressure. If a leaking rear main oil seal is found in warmer climates, this PI does not apply.
