Purchased a 2015 Durango RT with 28000 miles on it. Sorry if this is in the wrong place BTW. Couple minor things. Rattles etc I've fixed. I had thought I smelled burnt oil at stops. Stop lights etc and didn't see anything when I picked it up so I assumed some jackass at the shop just wasn't tidy when he put the oil in. Well I removed the engine cover and low and behold I see oil all around the intake manifold. Nothing major. It doesn't appear to have made it to the bottom of the motor or anything but annoying none the less since it was supposedly gone over with a fine tooth comb. (must have been missing some teeth). Anyways I removed the pcv valve and it rattles back and forth. So unsure if that's the problem. Seems to me maybe it was stuck before and was just never cleaned up . Odd for it to leak all the way around. The drivers side was worse but I think that actually could have been spilled oil. Also the transmission seems to downshift kind of hard at time when slowing down gradually. Last thing is that I swear I feel a knocking or at least hear it when going over jarring bumps. The roads in my town suck. Does anyone have any input on any of these problems. I've owned a HEMI before and we had the 8 speed transmission in our v6 grand cherokee. both a 2015 and 2017.

Thanks for your help!