Porsche IMS bearing replacement at Precision Motorworks

If you own a 986 or 987 Porsche Boxster, or a 996 or 997 Porsche 911 with the M96 engine, chances are that you’ve heard of the infamous IMS bearing issues. At Precision Motorworks, your Seattle Porsche specialist repair shop, we have performed these repairs many times over. The IMS bearing, which stands for Intermediate Shaft Bearing, is responsible for retaining and controlling the rotation of the intermediate shaft which runs lengthwise throughout the engine. The intermediate shaft is geared to the crankshaft and drives the rotation of the camshafts via chains. Because of the role it plays in engine timing, proper operation is vital, and failure usually results in irreparable engine damage.

Why do they fail?

While there is endless debate on the mode and failure rates of the IMS bearing, one thing is clear: the original sealed bearing design simply does not hold up to the test of time. The original design utilizes a sealed ball bearing that is lubricated when new but receives no supplementary lubrication during the life of the vehicle. Imagine a bearing that operates similarly to that of a skateboard or roller blade wheel, but subject to the relentless rotation and heat of Porsche’s first water cooled flat six combustion engine. The bearing has been known to fail in as little as 3,000 miles, but seldom lasts above 90,000 miles. Furthermore, Porsche supplied no suggested replacement interval or process, leaving initial buyers to discover this fatal flaw on their own.

Do I need to worry about IMS bearing failure?

The first question Porsche owners may ask is “is my car affected by this?” For models using the M96 (And in some cases the M97 engine) the answer is yes. The M96 engine was used starting in 1997 in 911 and Boxster models through the 2004 model year. Some later models including 997.1 911 Carrera and 987.1 Boxster into the 2005-6 model years also utilized this engine, and therefore were subject to IMS bearing failure. Notably, turbocharged models are not affected by these issues.

How can I tell if my IMS bearing is going bad?

While a used oil analysis (UOA) is a good way to understand the overall wear metals in your engine, and in rare cases, the state of the IMS bearing’s health, many prefer to replace the bearing for peace of mind. Our Porsche Repair Specialists in Seattle are well acclimated to this repair. Waiting for early warning signs can be a dangerous game since catastrophic failure can come out of nowhere. Preventatively replacing the IMS bearing is substantially more cost effective than any of the post-failure repairs.

How can the problem be solved?

The failure prone nature of these IMS bearings has been known for over 20 years, and as such, many technical advancements have been implemented to produce an IMS bearing update kit. Updated bearing systems have a failure rate of just a small fraction of the original design. At Precision Motorworks, we offer a full range of LN Engineering’s IMS Retrofit solutions. Our trained technicians utilize original LN engineering installation tools to provide a seamless, reliable installation. Furthermore, all LN engineering kits come with documentation for repair traceability. Having documented performing an IMS retrofit to your M96 engine vastly increases desirability and value upon resale.

For further information, visit https://imsretrofit.com/.

Once the IMS bearing is replaced, maintenance is equally important in ensuring reliability. Strictly adhering to 5,000 mile or 6-month oil changes is a must, and in cases of severe use, 3,000 mile or 3-month intervals is recommended. Additional research shows that proper driving habits also play a role in IMS health. Contrary to popular thinking, keeping your engine higher in the RPM range minimizes wear to the bearing- after letting the engine fully warm up first, of course. Even with all of this in consideration, due to the high stress on the bearing, LN Engineering still recommends replacing the bearing every 6 years or 75,000 miles for all current retrofit versions, with the exception of the “IMS Solution” which is a completely redesigned permanent fix.

What should be replaced during an IMS job? The IMS bearing is accessed by removing the transmission. As such, on manual vehicles it is highly recommended to inspect and replace the clutch and associated components during your IMS repair, at minimal additional cost. Also, additional inspections of the timing chains and guides, as well as the variocam actuators, is recommended.

Call or Message us at Precision Motorworks in Seattle to find out more and let us know how we can help you with your IMS bearing and other Porsche needs!