1999 Audi A6 Bad Camshaft Seal

noticeable miss while driving, lack of power

Car isn't a smartphone and so the battery is very unlikely to spontaneously combust - in 45 years of being associated with car batteries I have never even heard of it. When something like that happens there is always an external reason and finding and correcting that reason is really quite important if a repeat is to be avoided.

There might be a connection with your non-start or it might be a combination of age and condition and perhaps also the car is in a bad mood.
If I was faced with your problem I would, before assuming the solution to be complicated, prevent the fuel pump operating by disconnecting it or drawing the fuse and then crank the engine with the throttle held wide open.

The symptoms you describe are far from uncommon for an ageing vehicle and what it amounts to is an engine flooded with fuel, a situation that doesn't improve as long as injection continues. A clean set of spark plugs might be wise...

dealership for a $ or a local junkyard and swap out the guts

You would have to go to the dealership unfortunetly.

find a SPECIALIZED Audi mechanic with his own / family business ( NOOOO DEALERS !!!!!!) which may give 3 references - customers. After that, the only thing you should care would be the regular oil service. Splendid car, mine drove like a dream until the dealership f****d its engine.

IF YOU DON,T KNOW WHERE THE OIL&AIR FILTER ARE.IT WOULD BE BETTER FOR YOU TO TAKE THE CAR TO A LOCAL GARAGE AND GET THE WORK DONE THERE PLUS REPLACE THE OIL.WILL NOT COST MUCH.(GET A PRICE FIRST)..JUST KEEP BACK FROM AUDI DEALERSHIP GARAGES COST TO MUCH MONEY..

I have a 1999 A6 2.8, and my car was doing the same thing. However, after spending about a $1,000.00 I took it to another dealership. they replaced the fuel filter, it was dirty from putting cheap 91 gas in the car. Once it was replaced the car ran like new. I had to replace it around 80,000 miles. Hope this helps

MARKINGS ON THE CAMSHAFT SPROCKET AND TIMING BELT INNER COVER..AND ON THE LOWER TIMING BELT COVER AND PULLEY...HOPE I WAS OF SOME HELP TO YOU......

could be a bad seal on one of the camshafts. could also be from the valve cover. You need to wash the engine down carefully -don't get the wires wet and look closely for the oil path. is it engine oil or transmission fluid?

go to scottykilmer.com - i use this guy a lot - you just have to sign in - first name only! or whatever you want to call yourself. it is 100 percent free and he is an expert on all cars - you can expect an answer within an hour or so! this guy knows more than one person should know - trust me - no fee for free info? cant go wrong