We have one electromotor 110kw (simense) and pump (KSB) quite similar to this problem in company, The electromotor vibration is 18mm/s in the horizontal direction (but in the vertical and axial direction about 2 mm/s. all 4 bolts tightened vibration is high. If we loose them one by one no major change observed. But all 4 loose saw a drop in vibration.
we checked structure, it was ok
we checked soof foot , they were ok
we checked crack on soof foot and case with PT test but they were ok
we dont know , what do we do?!!!