I noticed the shell dino oil 10w40 had no slap. Its was warmer then, but still there normally would have been some. I just used the shell for a bout 20 minutes to flush out the engine after a gasket job. I would use it again, however I just dont feel right unless I have the anti-wear capabilities of a synthetic floating around in my engine. I just wouldn't feel right with dino. I guess I have to find the next best thing. I am the kind of person that has to have the best of everything in my car or it drives me nuts.
As you may have read my posts, I have spent over 200 bucks in the past 2 months with countless oil changes and different oils to find a solution, so far I have
-Mobil 1 5w30 - Piston slap loud
-Amsoil 5w30 - Piston slap Loud
-Amsoil 10w30 - Piston slap very loud, other knocking present
-Castrol GTX Startup Dino 10w30 - Quieter than all above
-Castrol Syntec 1.5 qt 20w50, 3 qt 10w30 - Much quieter, engine smoother during slap period
-Current - Mobil 1, 1.5 qt 15w50, 3 qt 10w30 - Same as Syntec, better gas mileage.
I found that going thicker seems to be the key. Now I need to know how much thicker I can go without damage or problems. Need advice on that.