Hello. I've got a 99 malibu with the 3100 V6 and about 93000 miles on it. The lower intake gaskets are about a month old and I've noticed what sounds like a rod or a lifter knocking when the engine's cool. I've read that it could be piston slap, but it knocks about 3-4 times a second. I would think the knock would be a bit faster if it were pistons doing it.
A friend of mine whom I trust has the same motor in his 98 Grand Am and he suggested oil stabalizer (didn't quiet it down) and then suggested 10W40. He's been running castrol 10w40 since about 60,000 miles. It now has 125,000 on it and he says it's nice and quiet.
My question is, have any of you had luck doing that and will the heavier oil cause problems with things such as the oil pump and what- not?
Thanks a lot,
John