I just scrapped an old chevy 6. 2L that has 2 pretty full tanks. The stuff inside smells like diesel, looks like diesel, and makes a mess on the floor like diesel. They truck sat for at least one year though with no caps on the tanks and has been contaminated with water, sand, etc. Is it worth trying to filter and use at all? I'm thinking that's it's a nasty headache waiting to happen and I should just leave it alone.