Using 10w-40 due to low oil pressure?
I'm using 10w-40 to increase my low oil pressure, which is caused by bad bearings. It increased the pressure from 5 psi to 9 psi over 5w-30 when I changed the oil this summer. But now it's winter here in Minnesota -- which weight should I use?
It seems to me that it's a matter of the least worst -- when the engine is warmed up after about 20 minutes, the 5w-30 will cause the pressure to go back down to 5 psi, which is bad. But when I start it in the cold, the 10w-40 is too thick to reach the top right away, which is bad.
Either way, the oil won't reach the top at some point. And important note -- the pressure is only low at idle and is fine at cruising speed, and increases to normal from low pressure when I accelerate.