I have a 2012 s197 V6 with 70k on it.
Bought the car back in July from a dealership. Single owner. Old lady drove around as a Sunday car.

Went to change spark plugs and first thing I notice was oil inside the upper intake manifold. Got to spark plugs and two of the plugs were coated in burnt up oil.

No oil in lower intake. Acceleration is lacking as well. Timed 0-60 6.8 sec.

Slight misfire from time to time. No codes. If under idle, will periodically drop to around 700 and then return...

Oil on sparkplug threads and upper intake manifold