I has been quite cold in my area lately. Buy cold, I mean like 0 or a few degrees below. We also had some snow which ahs made it a requirement to drive my 4WD Ford truck with the 4.6L engine. This is a 1997 Ford F-150 light duty which is the oddball with the 7 lug wheels among others. It is 4WD with a manual transmission. The truck has close to 300k on it and I was told it had a used engine installed when I bought the truck but have never been able to verify this. The engine runs well without odd noises or clanks and doesn’t burn or use oil. I have the O’Reilly brand 5W30 synthetic oil in the engine.
There has been a strange whine that comes from the engine at startup in these very cold temps. This only lasts a few short seconds and quickly goes away. I have the manual transmission in neutral so I figure it is engine related and not the transmission. It sounds like a gear noise or whine so I am assuming maybe the oil is too thick to get through the oil pump, timing chain, or similar.
This only happens at cold starts when it is VERY cold outside but I wanted to make sure this wasn’t a sign of impending failure. The truck runs well otherwise and I would gladly replace the oil pump if it were going out. I was also thinking about switching to a 0W30 as the truck is mostly used in the winter anyway if the oil not being thick enough is a possibility.
What do you think?