Compressor Cover damage – scoring

This image illustrates scoring out of the compressor cover profile, and occurs when excessive wear and movement in either the thrust bearing or journal bearing (or both) causes excessive movement in the rotor. In turn, this causes the compressor wheel to rub against the compressor cover, scoring out the profile. This makes the gap between the compressor cover and the compressor wheel too large, resulting in a loss of efficiency/power and excessive noise.