My wife & I bought a used 2002 Nissan Altima 2.5 SL from a large Nissan Dealer in our town in 2006. We did purchase a used car extended warranty for $1500.00, which would cover most major repairs up to 100,000 miles.
Before we picked up the car, we were told that there was a problem with the CC, and they were going to have it replaced. We had not thought if there were any reliability issues at that time. We never googled the question, until now.
The oil consumption was a concern since early in our ownership. I just kept adding oil between oil changes. Coolant levels were always topped up. The oil loss was not from any leaks, or burning out the tailpipe. There's no oil in the coolant, no coolant in the oil.
The service engine light came on, about the time we received a notice of the ECM recall. My wife made the appointment to have the recall issue done, and we also asked about the service engine light. We were told that the CC needed to be replaced, which was not covered, being over 12 mo./12,000 miles of the last replaced CC. We went ahead to OK the replacement. I questioned the reason a CC could have failed in 20,000 miles, and they could not answer it. The upper O2 sensor was also replaced at that time. The service advisor's explanation was that the failed CC ran extra hot, and caused oil to be consumed at the higher rate. This outside engine component, exhaust manifold/CC made the engine use more oil than normal. Doesn't make sense.
They changed the oil & filter at the same time. They also did tests to determine the oil consumption and it has good results. We drove the car and returned within 2-3 days (only about 2 hours of engine time & less that 100 miles, with the service engine soon light on again. They said they needed to reset the code. Within a couple of more days, the check engine soon light came on again, and this check needed the lower O2 sensor replaced. Now we are into the repairs at about $1200.00.
Within a few more days the oil was below the lower marks, near the end of the dipstick, and we added oil and called for a couple of days to the service adviser before he returned my calls, and we were back at the dealer for further work. We have been told that it has a cracked head gasket, and the beginning repairs are estimated at $1700-2000.00, although it could be higher. We couldn't understand why, until we found these past comments, and the same experiences from so many others. We picked up the car, and had to sigh that we were accepting the car back that was UNSAFE TO DRIVE according to the service dept of the Nissan dealer.