If you own a Porsche 996, Boxster 986 or a very early Boxster 987, Cayman 987 or 3.6 or very early 3.8 997, you are sure to have read some of the horror stories about IMS bearing problems. It’s easy to find tales of catastrophic engine failure and vast repair bills on Porsche forums, but what is less readily available is well-informed advice about spotting IMS bearing failure symptoms at an early stage.