Dark specs in oil

[SigShooter]

Purchased a 2007 Lincoln MKZ with 31000 miles on it about two weeks ago.Has the 3.5 Duratec engine.Dealer said they changed the oil and when I checked it before I bought it I thought it should have been cleaner, and noticed dark specs at the end of the dipstick.Well it was overfilled also,so I changed it today. Put in 5.5 quarts of Motorcraft 5W20 and a Motorcraft filter.I noticed in the bottom of my oil drain pan some larger soft particles that resembled what was on the stick. Could this possibly be sludge? I know the car comes with free oil changes for 1 year or 15000 miles. I'm wondering if it wasn't changed much after that.Do I have anything to worry about. The oil on the stick looks like it should now after a change.I measured the oil that I took out and it was almost a half quart overfilled, the morons must have put in 6 quarts instead of the required 5.5. This was at a Lincoln Mercury dealer.Anything I should do? Thanks for the replys. Dennis.

 

[tomcat27]

You are correct, it sounds like sludge. save a sample of the oil - perhaps even have the dealer do the next oil change. discuss the situation with them. can you see the valvetrain through the oil filler hole? if not, I would consider pulling a valve cover to look for sludge. believe it not, many people (especially those who lease cars or keep them onle a couple of years) rarely or never change the oil. perhaps use some auto-rx and use PP on short OCI's for awhile.