cohopefull

I've been changing oil for a long time and usually the fresh oil stays clear for some time but the new oil in my 95 Z28 turns black right away. The previous original owner swears it was maintained regularly. The car only has 44k on it. I m guessing he's either lying or the car has much more miles on it than 44k. Any thoughts?

1994BmtZ28

I'd say he may have changed it just to sell the car. Get the liquid Seafoam & pour half of it in the crankcase, drive it 200 miles MAX, then do an oil change (I drive 100 miles to keep from overdoing it). I inherited my father's Silverado & a couple regular oil change intervals cleaned it out pretty well...or as well as could be expected for 145K miles. The other half of the can's contents can be poured into a full tank of fuel & clean the injectors also FYI.

Mr99SS

newer oil has a conditioner called ... cant think of the name but it takes all of the bad stuff out of the engine = black oil

Injuneer

That would be "detergents" and "dispersants". Detergents clean, dispersants keep soot in suspension so it can be filtered and not settle out. Some black is normal. Immediate excessive black would seem to indicate a higher than normal level of ring blowby, unless its an engine that has never been properly cared for.

cohopefull

I was thinking the same thing, the engine is probably loaded with sludge. I also suspect it has 144k instead of 44k.