anyone on this forum a mechanic?

1997 A4 B5 model
1.8t with quattro
180,000 km
auto tranny, no tiptronic

here's the history of the problems i've been having

6 weeks ago: oil light comes on while on the highway.  took it to mechanic, says the oil pump gave out, replaced it for $400.   since then there has been a pinging noise coming from the top of the engine on startup that only lasts about a half a second.  mechanic told me this is normal after the oil pump is replaced/after an engine rebuild.

4 weeks ago:  temperatures drop to -50 celcius for a week and the car will  not start.  after cranking for 5 seconds the oil light comes on and starts beeping.  when it warmed up for 2 days the car started again, mechanic said there is no problem.  take car home and drive it for 1 day.  temp drops back down to -50 for another week.  car wont start. 

2 weeks ago:  weather lets up and we've had standard -20 celcius weather.  car starts, but pinging noise is still there on startup.  after running for 5 minutes the pinging is noticeable again, but not as loud as when the car is started.  there is also smoke coming from the passenger side of the engine that is present at startup and then stops after a few minutes (smells like oil).

if you can help me out with any of these problems; pinging noise, not starting in cold, oil smoke from engine, it would be sooo appreciated!!  i just bought this car in july and now it hasn't been running since before christmas!  this is a DISASTER!

Well the noise your hearing from the upper part of the engine is the hydraulic cam adjuster, it sounds kinda like a diesel engine when oil pressure isn't sufficient. I think the mechanic messed up when installing the oil pan and put too much gasket material in there, which breaks off and clogges up the oil pick up tube. All of these repairs are covered by audi regardless of mileage if you have oil change receipts.
The oil burning smell is from a leaky valve cover gasket and cam seal (where the adjuster is) which is directly over the exhuast.
I would get this car to the dealer ASAP, oil pressure problems can severly damage your engine.

any fault codes? wow this is easier than in my days is it tappet noise and yes it clears quick as it should but if it comes back it could be oil pressure or tappets/lifters they are hidrolik you know so lack of service could be the problem

im a real mechanic/engineer

well i just bought the car in july and it didnt come with any maintenance records.  i thought it would be alright since i bought it from a mechanic (the guy i'm still taking it to and who changed the oil pump). 
 
he had mentioned something about the camchain tensioner.  do you think this part needs replacing or is it not working properly because of a clogged oil pickup tube?
 
the car is at the mechanic's now but since he's ordered a used engine that will take about ten days to get into the city he wants me to come and pick it up.  i'm not comfortable driving the car in it's current condition.  should it be a problem to drive it back to my place then back to his shop when the engine comes in(10 kilometers round trip)? 
 
i'm seriously debating whether or not i should even be dealing with this guy with all of the problems i've been having, but when i talked to the local audi dealer they said it would take them 2 weeks to take a look at it!

When the 1.8L engine gets sludge its because of the faulty oil pick up tube design, not the oil pump. Look up my thread "Facts about oil sludge" and you will find all the info you will ever need.
If he never changed the oil pick up tube thats the problem. If its neglegted you may need the tensioner down the road, which is VERY expensive.

Out of all the cars I have never had problems with sludge in the early 1.8ts.(not saying that it couldnt happen) Now I dont work at Audi but I do beleave its only covered for 8 years. I would without a doubt get it away from that guy and have the oil pressure checked. Good chance the cam tensioner may need to be replaced. Where in the engine is the noise exactly coming from. Also is the abs light and brake light on togther?