I picked up a 2006 330i from a friend, it had a misfire cylinder 5, a bunch of codes for headlights (adaptive hid) tailights and other what nots. 

the day after i went and picked the car up i changed cam position sensors as i was told this was causing cylinder 5 misfire. swapped both intake and exhaust sensors and it ran better! but not fixed. 

next step was i removed cylinder 5’s spark plug to find it had a bunch of white stuff (looked like calcium) on it. knowing who i got it off of i figuired he drove it a while with the misfire cause it burbled more than it shouldve when let off the throttle.  REPLACED ALL 6 SPARK PLUGS WITH NGK IRIDIUM SPARK PLUGS. still didnt fix my issue. still cylinder 5 misfire on my code reader. 

I then swapped coil #1, and coil #5s places thinking it could be a bad coil pack, Nope. still Cylinder # 5 misfire.

Out of spite, i changed #1 and #5 on the injector rail around and wouldnt you guess it. STILL cylinder 5 misfire.

did a compression and leak down found its a stuck, gummed up or bad valve/valve seal. Cylinder 5 is practically dead. no scarring or damage just not online with rest of motor. 

all the bmw specialists in my area are telling me its not worth my time or money and would be in my greater interest to find another car. 

When i started it had 16 codes on the dash for various things. now im down to cylinder 5 misfire and as of yesterday, when it was cold after startup it threw a vanos code and a  A camshaft bank #1 timing over retarded code. i shut it off came back out on my break at work, cleared the codes and it ran fine (except misfire still there obviously.) Ive changed back to stock hid/xenon headlight assembly due to the headass before me stuck amazon  HALOGEN projector buckets in without doing research. still have headlight code but the self leveling system works, i can see and hear it upon startup.

this thing had the engine wiring harness catch fire due to a ‘thermal event’ in the oil level sensor. BMW took the car back and replaced the harness but left the oil level sensor (melted to the point you cant plug harness into it) in the poil pan and just black taped & zip tied wires wherever. some are against the engine block and are too tight for me to redirect them. some have insulation dried and falling off showing bare wire. 

Im not sure what to do or what my best steps would be and i was hoping someone here may have some insight.

Worth fixing? Next step?