Nissan Repair: 94 Altima, altima gxe, rear view mirror

Question
QUESTION: Hey I've got a 94 altima gxe. It has nearly 170,000 miles on it. Anyway, it runs fine. On occasion though, a smell of burning oil will come through the vents. The engine has so much grease and oil all over it, I'm not sure if it's just burning off or something because the car is not driven everyday. Another thing is the engine vibrates rather roughly, it's gotten to the point that it can make you nauseous to look in the rear view mirror. Along with the vibrating, comes a sort of metallic scraping noise. This appeared a little after the distributor, wires, spark plugs were replaced. The sound seems to be coming more from the passenger side, toward the middle of the engine. I'm afraid to start opening valve covers and such, because I get mechanics very easily, but I'm not too experienced and I don't know what will happen lol. Plus, I'm not sure if that's even it. Lastly, and not so important...the passenger side headlight keeps going on and off. It seems like there's a bad connection because when I move the wires up it comes back on. With the engine vibrating as it does though, it doesn't stay on long, or it goes off as soon as the car is shut off or a significant bump is hit. The car was in a small accident on that side, so I'm sure that has something to do with it, but would you think it's the whole wire that needs to be changed (and how easy is that to do?) or something else? Sorry not meaning to bombard you, but you seem to know quite a bit, and it's rather hard to catch you when you're not maxed out. LOL...thanks.
ANSWER: Kenneth,

I would steam clean the engine first and then check the motor mounts.  It sounds like the motor mounts are defective.  Also, the valve covers are an easy replacement to stop much of the oil leakage.  The headlight problem is due to the master headlight switch on the column.  If the light has a defective ground it could be that too.  But, a 94 year model is probably the headlight switch.

---------- FOLLOW-UP ----------

QUESTION: So as far as the metallic scraping noise...it's not fast paced, I only hear it at idle, that doesn't mean that it doesn't speed up or happen during the drive, but it's hard to hear from inside. Also I did forget to ask, the airbag light came on, hell I long time ago I guess (it used to be my girlfriend's grandmother's car, now she has it) and I don't know what it is? It worries me a bit, but I know nothing about airbags. Is it just the sensor or would you say something more drastic? Sorry...and thanks for the prompt reply.

Answer
Kenneth,

The metallic scraping sounds could come from the timing cover.  Get a screwdriver and put one end on the cover and the handle against your ear.  Let me know what you hear.  If the airbag light is on the system has a fault and you will need to have a scanner to find the cause.  The nice part is a wrecking yard can source you the parts.