Drivetrain Knocking noise when I turn key engine off

AnthonyA1234

5 Year Member
Aug 17, 2020
669
111
63
Florida
Got my car back from the body shop and I noticed something new that it didn’t do before. Now when I turn the key with the car off to prime the fuel pump I’ll hear the fuel pump behind me as usual but in the last couple seconds of the fuel pump priming I’ll hear a quick low knocking sound from the engine bay. If I turn the key again to prime the pump again it will not make the noise again. It only happens the first time. Any ideas on what this could be?