Mitsubishi Repair: 91 Eclipse needs help bad, coolant level, valve seals

Question
I have a 91 eclipse gs 1.8 L auto trans. I just had the head gasket replaced by a mechanic (not certified unfortunatly)and in the process the valve seals, injectors, rings, and main oil seal were also replaced. The head was sent in and resurfaced. Since I got the car back I have had to put at least 2-3 quarts of oil a week in it and i have grey/white smoke coming from my tail pipe. The smoke smells like burning oil. When I am at a stop the smoke is heavy and lightens up when I am in motion but is still kind of thick. I have checked my spark plugs and 3 of the 4 appear to be good the plug in # 1 cylinder has black sediment on it. I can't seem to figure out what is wrong. My coolant level is good and hasnt gone down any. Could the rings have been done wrong or the seals? My coolant level is good and hasnt gone down any. Also my idle seems off. When it is park and is the it will idle between 1500-2000 rpm and when it is drive it will idle @ approx 1000 rpm. is this normal? If not what should I check?  And on the trannsmission, it shifts hard going from 1st to 2nd and shifts at a high rpm (3500) and the downshifts hard from 3rd to 2nd and 2nd to 1st. it is hard enough the car lurches and shakes. Car has little to no power going up hills and is slow getting up to speed from a stop. I had to replace the pulse generater (its what the dealer called it) to get the o/d to work and it has shifted like this since i replaced this cable. Could the wire be faulty or am i using the wrong tranny fluid. Any advice would be very helpful I was told i may have to replace my engine and am hoping this is not the case. THANK YOU

Answer
Chris,
You're definitely burning a lot of oil. I don't think you'll have to go to the extremely of replacing your entire engine, but you need to have this problem taken care of ASAP.  Burning 2-3 quarts per week is a sign of a serious problem.  This is typically caused by bad rings.  Your mechanic may have installed them improperly.  Bad valve seals can also cause this problem, but you'd have to have several bad ones to go through as much oil as you are burning.  You need to go back to your mechanic and let him know the new rings he installed did not seat properly.  Hopefully, he will honor his work and fix the problem at no additional cost.  He should first do a compression check to find out which cylinders are loosing compression and causing the oil to burn in.  From your description, it may just be the #1 cylinder; which would explain the black spark plug.  When your engine is at normal operating temperature, it should idle around 800 rpms.  It will idle higher when the engine is cold.  But worry about getting the burning oil problem fixed first before getting into the idle speed issue.

As for your transmission, this is something else that would be hard to figure out the problem until your engine is running properly.  If you haven't changed your transmission fluid and tranny filter within that last 30k-40k miles, this is a good time to do it.  Your owners manual will tell you the exact tranny fluid that you should be using.  If once you get your engine functioning properly, and your shifting is still rough, you should have your transmission inspected by an experienced transmission shop.
Good luck!