Straight Talk about the IMS Bearing in the M-96 and M-97 Engine

Those 3 letters stand for something big – Intermediate Shaft (IMS). There has been much talk and information about it on the internet, some of it actually true, most just stories by people who have had a bad experience. Here are the nuts and bolts of it.

Porsche is no stranger to the IMS. Porsche has been using an IMS for along time. The 547 Carrera engine had one, in fact every 911 ever built has one. In the early engines, the IMS is known as a “layshaft” and does not present issues, even though it had the exact same job as the current IMS in regard to driving the camshafts. The problem is not the IMS but the IMSB (Intermediate Shaft Bearing) in the M96 and M97 engines. 

Corner Entry

 

A few months ago I had the opportunity to take a first drive in the new 991. This particular car was a Carrera S, equipped with PDK. The venue was not the street, but (as deemed by some), the best track in the world, Watkins Glen International. I would drive several laps to show my student around the track prior to him taking the wheel. Life is sometimes tough – I would drive the car for the sole benefit of my student, but I certainly would not enjoy it.

 

Tracking Out

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“Hey there!” I said cheerfully as I approached black Cayman S. The white group driver was already strapped into his car and looked a little confused about why I was approaching him, helmet in hand, and asking how his day was going.

Once in a while, right smack dab in the middle of a perfectly good driver education event, we shake things up a bit and do something called a “white blitz.” For the uninitiated following along at home, white group drivers are our first “solo” run group, meaning that they are not assigned instructors at events. Once in a while, though, we like to do a check up. Instructors randomly get into white run group students’ cars, usually without warning, as they prepare to pit out for a run group. Sneaky? Maybe. But the element of surprise is sometimes fun. Sometimes.