Problem: Intermittently my Nissan Maxima 2002, with 90K will consume a large amount of oil.
Latest episode 1.5 quarts down after 500 highway miles. Previous 500 highway miles no oil consumption at all. This occurs periodically.
No physical oil leaks.
No oil in coolant.
No eivdence of oil burning on tail pipe.
No evidence of oil spray on tail pipe.
Compession check, normal.
Dealer has no idea of what the problem is. He suggests two options: replace pcv valve for $150 and/or/ replace valve covers and pcv valve baffle for $1,000. He admits however, that these could be shots in the dark and he cannot guarantee that either action will solve the problem.
Any ideas out there?