I have an 06 Ranger 2.3L 149k miles. I've noticed my lifters starting to knock on cold start but go away after a few seconds running. Did some search an found some people swapping a qt of engine oil for a qt of automatic transmission fluid, because of all the cleaning agents ATF got, during an oil change. No consequences of any sort an theyve been doing it for years. Is this true? If not, what can I do/use to avoid having them go completely bad?
That sounds like a bit of an old wives tale. Engine oil has to deal with combustion by-products whereas ATF does not.
Anyway, I would just use a very high quality oil that meets SN+ and GF-6a specifications (for best cold flow performance). Change it often and use good quality filters.
If you want to get really nutty about it you could use a block heater to preheat the oil.
But I wouldn't worry about it too much. An engine can go on rattling like that for a loooong time. It's just what engines do as they age.
Thanks for the quick response! I got one more though. What kind of oil would you recommend? I see you said about SN+ and GF-6a but I have very little knowledge on what that means. I've been using Castrol GTX highmileage 5w-30.
GF-6a is just standard proposed by the International Lubricant Standardization and Approval Committee (ILSAC).
Let me give you another example ...
Lets say you expanded a section of your house, and you need to install light switches. You want everything to be by the book so the inspector gives you a permit. He wants your switches to meet a certain standard (which guarantees that the switches pass certain safety tests). He will say you need "UL listed" switches, or something like that.
It's the same with your oil. These designations simply indicate that the oil has passed certain performance metrics. GF-6a is at this time the highest agreed upon standard and provides the best lubrication for engines.
Any standards that an oil meets will be printed on the label. So just read the bottles when you go to the store.
Ignore marketing baloney like "high mileage", "synthetic" etc. They are lies anyway.