I have a 2004 Buick Rainier (don't ask) with the aluminum 5.3L, LM-4 V8. They're known for enough piston slap noise to convince you, no doubt about it, the crank is about to knock enough to tear out the bottom. *Everybody* says, "don't worry about it, it's just the way it is". But.... I was out of town and had time on my hands, i.e., needing some time away from relatives, and I dropped into a quick change place and told them to just use 5-30 PYB and out the door. Two things: normal use is 5-40 Motul (mostly PAO I assume) and the piston slap is there but only about 25-30% as loud. Secondly, it occurs to me that there may be some washoff of one add package for the new one and it has not had time to *deposit* the new package. But the other concern is the possible change of HTHS has had the most effect. Bearing in mind that the slap will never completely go away:
Would piston slap in an aluminum motor be *helped* from a wear standpoint by going to and sticking with a very high moly like RL or similar? Or,
Would staying with an oil with goodly HTHS be enough to reduce the noise AND limit the wear? In other words is expensive, high moly RL or similar indicated or should I just stay with (the much less expensive) Motul?
Even if *they all do it* that absolutely gets my attention on cold start! It can still be lightly heard at idle when warm. What say?
Cheers and thanks.
Would piston slap in an aluminum motor be *helped* from a wear standpoint by going to and sticking with a very high moly like RL or similar? Or,
Would staying with an oil with goodly HTHS be enough to reduce the noise AND limit the wear? In other words is expensive, high moly RL or similar indicated or should I just stay with (the much less expensive) Motul?
Even if *they all do it* that absolutely gets my attention on cold start! It can still be lightly heard at idle when warm. What say?
Cheers and thanks.