Postby smj999smj » Tue Feb 26, 2013 7:17 pm
Spark plugs are supposed to be replaced at 105,000 miles. There have been several causes of oil burning in these engines (a lot of the time you won't see smoke out the tailpipe because it gets burned up in the catalytic converters). Some have said it was due to a bad/clogged PCV baffle in the valve cover, requiring replacement of the valve cover. Obviously, a stuck PCV valve could be an issue. There have been a few that have had the power valve screws fall down into the engine, but I doubt that's causing your issue unless it cracked a piston. A large number of VQ35DE engines burn oil due to lack of piston oil ring and lower compression ring sealing due to the tapered cylinder bores (as engineered from the factory). Nissan came out with piston rings to correct the issue, but, of course, this requires removing the pistons and honing the cylinder bores. 1000 miles per quart is excessive and one would have to worry about the damage it's doing to the upstream catalytic converter(s).