My neighbors son has a 2009 Chevy Cobalt automatic transmission. Oil is "disappearing" when he drives the car with no apparent oil leaks under the car when parked. They simply cannot figure out where the oil is going as there is no apparent visible signs of oil in the engine bay. is there a most likely cause that can be checked to isolate where the oil is going?
Mileage?
Wow, start with this -
If there’s no leaks, do a wet & dry compression test. Is the inside of the exhaust covered with oily residue? Does the exhaust smoke when the engine is running?
how much oil is it consuming?
GM states that 1qt every 2k is "accepted"
Oil is full and drove less that two miles engine starts clanking and oil light comes on and not registering on the dipstick.
OK a gallon of oil in two miles is pretty bad.
Check the oil filter, the drain plug, and the oil cooler lines (if any). Also see if it's getting into the coolant. Other than that I'm stumped.