2015 Xterra Pro-4X
Does the transmission fluid have a burnt smell to it? When was it last changed that you know of?2007 S, 158k
About a week ago I drive to a doctor's appointment (roughly 10 city miles), truck runs perfectly normal. Go to back out of the parking spot and reverse doesn't want to engage, just kind of revs and sputters, eventually engages. Everything else seems fine until I'm almost home. Going through an intersection from a complete stop, truck hardly has any power in first gear, not completely dead just rough. Bit of a jerk into second and seems fine from there.
Parked for two days while I research the problem. Go to take it around the block, reverse engages no problem. First gear is fine at first. Round the corner and first gear gets real rough again and loses all acceleration, just revs.
Parked for another two days. Against my better judgment, I decided to try and get it to the cleaners just down the road so I can get it posted to sell. Reverse is fine. Goes into first through third. This time though, I notice a whirring/buzzing noise coming from underneath while the accelerator is pushed which has never happened and it doesn't seem like the timing chain humming. Once back down to first, it loses all acceleration and just revs. Coast into a parking lot and turn it off. Sit a minute, crank back up and goes into gear. I'm lock two blocks away from home so I basically just coast back.
I've been scouring the internet and trying to diagnose what I can with what little knowledge and resources have.
No knock or any other noises besides the buzzing.
It's not SMOD. Transmission fluid is a little dark but not milky or low and no residue under the radiator cap.
No codes are being thrown except for the fuel censor (it's been out for a while, just haven't had time to drop the tank and replace).
Not running hot, has full tank of gas, and oil is fine.
Crankshaft position sensor died and was replaced last year.
Sorry for the long OP but if you made it this far, thank you. What do you guys think? Would somewhat old transmission fluid cause this much of a problem? Could it be another sensor somewhere even though I don't have a code for it? Solenoids? I'm running in circles and don't have money to just throw at a shop in hopes they figure it out.