I currently drive a 1998 Chevy Monte Carlo with the 3.1L V6 and have used Mobil 1 5w30 in the car since I purchased it last year with 27,000 miles on it. I might add that the previous owner also used Mobil 1 but he used 10w30 and changed every 3-4 thousand miles. I have continued the same intervals while continuing to use Mobil 1 or PureOne oil filters just like the previous owner. My real concern is a metallic "rapping" or ticking sound when I start the car up of a morning and again when I leave work of an afternoon. The car now has 39,000 miles and runs great but the clicking bothers me. The clicking stops after the engine warms (2-3 minutes.) Should I try another oil, oil filter, or what should I do? Thanks for any advice.