Yea i think i misused the word sludge, the videos i saw on youtube was not same as mine but the oil was really dark and abit thick on the bottom once the oil settled in the catch pan. I double checked my old oil filter today, the seal seems okay. There was a part of seal that was not perfectly round has a slight maybe 1mm bend but other that that not sure why it caused a leak. Maybe moving from Florida 90F to NY 30F caused the seal to loosen.

 

You have to stick your finger in some new oil and rub some on the new rubber gasket on the new oil filter before you install it. It keeps the gasket from binding when you are tightening it up.


Edit: I've seen oil filters installed too loose leak and I've seen oil filters installed too tight leak.

 

If you have been running synthetic oil, there should not be a lot of sludge; another oil change, with the oil hot or warm, should flush any out, like the other guys suggested.

Even though the oil probably is fine for years just sitting there in the engne, I'd suggest going by the oil change reminder system, regardless of mileage. I'm pretty sure it will remind you to change it every 6 months at least, regardless of mileage. I use full synthetic oil; and I change it when the computer tells me to change it, sometimes this is less than 3,000 miles because of the 6-month thing. I know this is probably overkill, but it's one less thing to worry about.

 

Forgot all about the oil filter i saved that day when i changed the oil. I finally opened it up and found tiny tiny silver speck on the filter(smaller than the period on end of this sentence). These specks are barely visible under the light and i found about 60 of them scattered on the filter. What does this mean? I havent experience anything abnormal so far and i did change the oil again few hundred miles after(havent checked the oil filter yet).