loud condenser unit

Had a new coil and condenser unit installed a few weeks ago (Armstrong 3 ton on an Armstrong 90 furnace) and was standing outside near the unit over the weekend and noticed when it shuts off it was really noisy like the compressor thuds against the case. Have not called the company that did the work but was wondering if they forgot to remove a shipping bolt or something easy or are newer compressors just that loud. Thanks!