I recently purchased a 2012 Altima with 39k original miles. A beautiful car that apparently the previous owner did not change the oil and found out subsequent to the purchase that Nissan voided the engine warranty. On start up, it smokes quite a bit for the first 10 seconds or so and then produces the normal vapor on colder mornings. It doesn’t happen every time and it really doesn’t have a consistent pattern although I would say maybe 6 out of ten start-ups the smoke is visible and other times nothing. I am using a quart of oil about every 500 miles. What would you suggest to help me?
I am sorry to hear of the potential sludge issues with the motor. It is likely that the morning smoke has a lot to do with the position of the valves when the motor comes to rest. Perhaps you have a very dirty or worn valve stem seal. If the motor comes to rest with the valve closed, then oil does not leak down on top of the piston. If the weak seal valve comes to rest in an open position, then you get drips of oil down on top a piston, before the oil has time to drain down to the oil pan. Thus you have sporadic smoking in the morning.
It is likely that you have a fair amount of sludge in the valve train, whereby the oil is having difficulty draining back to the oil pan for re-circulation. When this occurs then oil floods the area under the valve cover, and some oil will get sucked right out through the PCV valve and get burned off.
My best suggestion would be to run the fast track application for heavy sludge. You can review it over at www.auto-rx.com. I would suggest looking at the PCV valve for liquid oil being present at the valve or associated plumbing. As only vapors, not liquid oil should be passing through the PCV valve.
I would recommend replacing the PCV valve before starting the cleaning process. I would also recommend running 2 bottles of Auto-Rx with a conventional oil for faster cleaning results and also economy. By economy, I mean faster cleaning, will mean less make up oil during the cleaning process. Hopefully in the first 1000 miles of operation that quart per 500 miles will start to slow down.