I have a 2006 honda fit with a 1.3L i-dsi engine and an automatic transmission. The car starts up ok even if the engine is cold but when i shift it to drive (when cold) the rpm just jumps up and down from 1k to near zero accompanied by vibrations/shakes (its scary, i can really feel it shake). It runs and shifts good (like a car without problems) when its in operating temperature with the AC off but when i turn the AC on, it hesitates and idles so bad.
As i checked: The check engine light is off and no codes are read (i dont know why its off when you can really feel that somethings terribly wrong) and the 4 inner spark plug wells were wet with engine oil.
Im guessing its either a worn VCG or a clogged PCV valve but before i bring it to a mechanic i want to have an idea as to what else might be the cause of all this. Can you guys help me?