I have a 93 90s and right at the top by where the oil goes in there looks to be dirt just sitting there which I'm sure is threw out the rest of the engine. It's time to change the oil and was wondering if there was anything I could use first to flush all the dirt out before putting the new oil in? I know it's not metal I checked it is dirt. Thanks for the help.

 

there is no dirt, its sludge.
Sometimes best left alone. However if you want to clean it there are couple ways.
1. seafoam, follow the instruction on the can
2. flushing with transmision oil, I remember someone using it to clean the engine, best bet is google.
3. using a flushing addictive, follow the instruction on the back of the can.
4. blending 2L of gas in 3L of used oil and old oil filter. Then let it run through the engine. monitoring the oil presure all time, not reving above 2000RPM. about 5 min is enough.

Remmemeber to use good oil like Mobil1.