Note to self, never do more than one fix at a time to narrow down potential side-effects easier. After changing the oil and transmission fluid flush I noticed a subtle yet noticeable engine noise that is almost like a faint shimmy or shudder that wasn’t there before. I don’t know if it’s the transmission fluid or the engine oil. I bought the Pennzoil 0W20 last year on sale along with 5W20 which I’ve used over the summer, figuring the “0” would be better for winter. But after pouring it in the engine seems to sound louder, even at idle.
Not sure what gives, but will drive it a little longer to see if it works itself in. If the whole thing starts bothering me enough I’ll dump this fluid and replace it with a jug of Pennzoil Platinum 5W20 that I already bought. Next I plan to buy Castrol Edge 5W20 oil just to see how it compares to ones I previously tried: Pennzoil Platinum and Mobil 1.
BTW, after running the Techron Fuel System Cleaner through the last full tank of fuel, I did indeed notice that the engine oil was very dark at just 5,000 miles. Normally Pennzoil stays brown longer on previous changes I went as high as nearly 7,000 miles and it wasn’t that bad.