Adding a quart every 2,000 miles is completely normal.

Why does it happen? Because your engine is not perfect

So it is burning a little bit of oil. EVERY car burns oil. Out of a thousand cars your car's age, your going to get some that burn a quart every 10,000 miles, some that burn a quart every 5,000 miles, some that burn a quart every 2,000 miles and many many cars will burn more than a quart every 2,000 miles. In fact, most cars with 70,000 miles on them will burn at least a quart every 2,000 miles.

A car is not an "oil burner" until it burns more than a quart every 750 miles.

My 96 850 with 70,000 miles burns about a quart every 1,000, and I've babied it since birth.

Thats just the way it is.