Horrible idea. Heavier weight oil DOES give you better ring to cylinder oil film, BUT is also flows MUCH slower so the engine runs hotter, oil degrades faster and sludges up, and causes engine wear. Read this article on higher weight oil
http://ricksfreeautorepairadvice.com/wha...
Scroll down towards the bottom to see what it says about heavier weight oil in an older car
You are either burning oil or you have very low oil pressure. With the temperature down where you is at, the oil will always have a pressure. You go to say 5W20, your oil pump will not be able to pump 5 weight oil out for the clearances of the oil pump are too great. It is like a thick dump or diarrhea. One you don't have any control over so cannot squish "uphill" or through the engine to all the parts because it is as thin as water.
You only did the head - not the bottom end which is the part that pumps the oil into the head and I guess he figured with the miles on the Nissan, this was guaranteed to get oil into the heads where it is needed.
Why did you not ask him?
probably a high mileage vehicle using oil.............
I have a 1993 Nissan D21 (hardbody)
2.4l 4cyl recently I had the head rebuilt by a machine shop cleaned and sonic tanked new radiator and hoses new water pump new oil pump new belts all new hoses I was told by mechanic the block and pistons are good just needed a good cleaning to pistons now that he finished the job he is recommending 20w50 oil and it concerns me to switch he already had me switch from 10w30 to 10w40.
Just a side note I live in Florida were it is constantly 85 degrees and up (humid) and short winters that stay above 50 degrees rarely below that.
