[Chuck W.]

First off, great looking car. You will love it. I have a 2001 S I bought new. It is currently at 25,000 miles.

It is difficult to know what IMS you have without looking at the housing. And to see this you have to remove the transmission.

According to a Pelican article my Boxster has a dual row bearing. The car was manufactured in March of 2001. I found my engine number (passenger side of the engine) and it falls within the dual row range. HOWEVER, every respected mechanic on this board has found that this is not always correct.

It is a tough call whether to do the IMS baring replacement or not.

In the main time... enjoy the car.

Here is part of the Pelican article....


Which Bearing is Inside Your Engine?

The first step in replacing the bearing is to figure out which one you have in your engine. There were three variations installed over the years. Early cars typically have a large double row bearing that has a snap clip inside the bearing. Porsche later went to a single-row bearing design when the timing chain design was modified (see Figure 5 for a comparison of the two). Then, around model year 2006, Porsche installed a third version which is not replaceable. The supposed cut-off on engine numbers are listed in the Porsche factory Technical Bulletins, but unfortunately, these numbers are not 100% accurate, so you need to look at the bearing housing that is installed into your engine in order to be 100% sure as to which bearing you have (see Figure 5).

The question of which bearing is inside your engine is probably the number one question asked when people read this article. Porsche's electronic parts catalog lists the following engine numbers as the cutoffs for the various engines:

Engine Number - Model - Bearing Type

Up to engine # M 651 12851 - Boxster 2.7L M96.22 - Double Row Bearing
Up to engine # M 671 11237 - Boxster S 3.2L M96.21 - Double Row Bearing
From engine # M 651 12852 - Boxster 2.7L M96.22 - Single Row Bearing
From engine # M 651 11238 - Boxster S 3.2L M96.21 - Single Row Bearing