engine rebuilt and using oil? on 2001 Toyota MR2 Spyder

I had my engine rebuilt a little over a year ago. It started using oil right away. They have been checking it on a regular basis using different weight oil. We are now using 2050 weight oil and it is going through 1 to 2 qts every 100 miles. There doesn't seem to be a lot of smoke coming from the exhaust and they keep telling me they don't know why it's doing it. I think it is just plain burning it and they are trying to ignore the responsibility. What do you think could be happening other than burning it since there are leakes showing either?

Asked by for the 2001 Toyota MR2 Spyder
This is wrong it should not be consuming this quantity of engine oil. It will only get worse and it will only end up degrading the catalytic converter if it has not already damaged it. The oil rings/ piston rings have a problem or are installed wrong. The cross hatch in the cylinder are incorrect. Valve guides or seals have failed or PCV system is not operating correctly. I build a lot of engines, race and street.
My advice is to go back to the garage tell them you are unhappy with the oil consumption, they have had ample time to rectify the problem. Tell them you want a second opinion and wish to take your car to the Toyota dealer and that you think there opinion should be binding.
You are ging to be told the engine will have to be disassembled! You need to try to solve the problem amicably other wise you will have to go to small claims court, negotiate with the Better Business Bureau or Bureau of Automotive Repair.
2 more answers
I have a 2000 Toyota Mr 2 Spyder. Depending on how hard I drive my car, determines how often I have to put oil in it. The handbook tells you that if you drive the car hard, it will use more oil. I am not a mechanic, just sharing information that in your case may be useless.
This is a common problem in pre 2003 models. See, the rings wear, which throws oil into the catalytic converters in the manifold, which degrades the honeycomb in the cats, causing them to fall apart and drop into the main catalytic converter, causing an increase in backpressure, causing the rings to wear out faster, causing more oil to get burned, etc. The car went from eating a quart of oil every thousand miles to eating a quart of oil every 500 miles in only 10,000 miles.