For starters:
1 - Based on your pics, your spark plugs are junk. I bet you still have the factory champions in there. The plugs are known to have there porcelane portion loosen up after time and start to cause blow by past the spark plug causing what you have in the above pictures.
I bet if you pull out a spark plug it will look like the above picture. Thats what a plug looks like after having the ceramic loosen up after time
Long story short, you need new plugs and wires......and use dielectric grease on the install....
2 - Stick with the 5-30w oil, the motor does not need anything thicker unless you already have other issues.
3 - Goto Autozone and pick up a can of K-W engine flush. Pour the whole can into the engine and run the car for 10minutes. Atleast 2 cycles of the cooling fan, wich ever comes first.
4 - Now as for oil....If you stick with conevntional motor oil, change it every 3months or 3k miles. The main reason for the 3 months is conventional motor oil breaks down and gives off acidic fumes wich in turn effects internal components. I tried the 5K interval with Mobil One oil and I will never do it again on a daily driver that see's city and highway miles! The motor oil looked like diesel oil after 5K miles, and that was with Mobil 1
5 - If you are going to be that forgetfull when it comes to a simple oil change, switch to synthetic. Its a little bit more forgiving than conventional oil. You dont have to worry about time for oil change intervals like conventional, just mileage.
Ok, there's my 5cents worth of info.....C-YA!
