I worked a summer job for a Mitsubishi dealership that had a shady practice of adding what detailers call motor honey to trade ins with high miles.This stuff is truely nasty. Thicker than honey from what I remember, quieted clacking valves instantly.

Basically it's a 100+ weight oil that sticks to EVERYTHING inside the motor and makes it run quiet for a few hundred miles. This of course is a bandaid for a worn out motor and the oil pump and filter will quickly clog causing the motor to overheat and die.

The cover up was a "complimentary" oil change with regular 10w40 and yes carwash before the unsuspecting prey would drive their newly purchaed bomb off the lot.

Salesmen called this "the reach around".
Long story short, if the oil on the dipstick feels sticky or stretches between your fingers RUN AWAY!!!