Nissan Repair: nissan ac and rattle noise, gas mileage, pin hole

Question
Hi,My nissan has 127,000 miles on it and i use 10 30 motor oil and noticed it has a rattling noise when i accelerate slowly,can it b the oil or maybe off timing? Also i noticed a pin hole on the metal part of the a/c hose and tried 1 can of sealer but it didn't work can i sorter it or add a few cans of ac sealer. Thanks

Answer
Louis,

Try higher octain fuel or retard the timing.  That is, if it is spark knock.  If the knock is internal then you could use a thicker oil.  But, Nissan tolerances are tight and thicker oil than what you are using will rob you of horsepower and gas mileage.  The hose for the airconditioner need to be replaced.  No amount of sealer will correct a hose leak.