I have a 2005 H2
Mileage \ 130.000 miles
from one year ago I started to use 20w50 oil
Oil pressure is good @ 40
GM Recommended oil is 5W30
My Question :
Is it normal & safe to use 5W30 or 10w40 after 130000 miles & After one year of using 20w50 ?
I live in a hot area
We are now in the winter And I began to hear sound like tic tic tic tic When I run the car in morning & Stay until the engine heats up then the sound disappears
I locate the sound from the last nail of the exhaust (( The nearest one to the driver ))
Is It the engine valves ?
If it is the engine valves, Is it possible that if I change the oil from 20w50 disappears?