Bought a 2010 BMW X3 with a blown engine. I replaced the engine. Now I have a yellow 4x4 and brake light on. It drives and feels like it's stuck in 4x4. Turned wheel hard left and hard right. Lights went off. Then after 2 miles they come back on. Checked and cleaned all 4 wheel sensors, Serviced the transmission, replaced the transfer case plastic actuator gear. Has a small whine toward the rear of the car. Any idea how to fix? Pullin my hair out, what's left!! Any help would be greatly appreciated!