Between 1998 and 2012, Porsche produced just over 388,000 911 models across the 996 and 997 generations. Both these generations share a similar flat-six naturally aspirated engine (engine codes M96.01 to M96.05 and M97.01). While these engines deliver thrilling performance and a glorious soundtrack, they do come with a known weak point — the Intermediate Shaft (IMS) bearing.
What is the IMS Bearing and Why Does It Matter?
The IMS is a steel shaft running through the heart of the engine. On one end, it drives the cam chains via a sprocket; on the other end, it powers ancillary components through a pulley. The IMS bearing supports this shaft inside a housing, allowing it to spin smoothly. These bearings rely on self-lubrication to keep temperatures down and ensure flawless operation.
The problem occurs when the lubricant inside the IMS bearing dries up or leaks out. Without proper lubrication, the bearing overheats, starts to break down, and sends metal debris (swarf) into the engine. This debris can block vital oil pathways, causing severe engine damage. In extreme cases, the bearing race can collapse entirely — leading to catastrophic engine failure. This issue primarily affects 911s, Boxsters, and Caymans with M96 and M97 engines produced between 1998 and 2007.
Has Porsche Fixed This?
Good news — Porsche upgraded the IMS and bearing design starting with the 2007 model year, solving this problem for newer engines. However, for earlier models, many aftermarket solutions are available, and we’ve fitted and tested a variety of them ourselves.
So, When Should You Replace the IMS Bearing?
From an engineering standpoint, the answer is simple: as soon as possible. Some believe that if your IMS bearing has lasted over 20 years, it should be fine; however, given the potential cost and hassle of a failure, prevention is the better approach.
A failed IMS bearing can result in engine repairs costing upwards of £10,000, or worse — an engine that’s beyond repair and needs replacing entirely.
The Smart, Cost-Effective Solution
The best time to upgrade your IMS bearing is when you replace your clutch. Since both jobs involve accessing the engine internals, combining them keeps labour costs low. The upgrade typically costs around £600 plus VAT when done alongside a clutch change.
So it really comes down to a simple choice: spend roughly £2,000 now for a clutch replacement and IMS upgrade or risk a much larger bill for engine repairs later.
Our team has over a decade of experience fitting IMS upgrades. We use a proven, high-quality part backed by a 5-year warranty — including an additional oil feed system designed to prevent the bearing problems we’ve discussed.
If you own a 996 or 997 Porsche and want peace of mind, get in touch with us to discuss upgrading your IMS bearing before it’s too late.
