5/30 is the most recommended I believe the oil industry makes us all believe we must use the right brand, weight & type ( this oil for 4×4’s or this one for high mileage cars) of oil most of it is bologna I would look else where for your problem maybe low on oil but I don’t think because you used castrol instead of quaker state or you used 10/30 instead of 5/30 it will make a difference I was a mechanic for 10 years I DON’T BUY IT
there is a fuel system cleaner made by everwear that helps evaporate fuel moisture. you can find them at most parts stores. your car calls for 5w30, but most shops carry semi-synthetic, which is better protection. i work for goodyear, and we carry kendall semi-synthetic, so find a goodyear/gemini dealer and have it done there…we also charge less for oil changes…lol.
run a little thicker oil in the summer = 10W-30
and in the winter the thin stuff - 5-W30
Nissan themselves list anything from 5w20 through to 20w40 semi synthetic based oil dependant on where you live in this world, I work for an Edinburgh based Nissan dealer and have always used 10w40 semi synth without any problems, problems occur when you start using different types of oil which obviously are made with varying additives which protect and also cause wear within the engine.
Go back to using a named brand of 10w40 semi synth oil and see how you go.
Cheers
Andy