If you’ve spent any time researching used Porsche sports cars, chances are you’ve come across the term “IMS bearing failure.” It’s a topic that tends to raise eyebrows among enthusiasts and new buyers alike—and with good reason. The intermediate shaft (IMS) bearing is a small but critical engine component, and when it fails, the results can be catastrophic.

However, not every Porsche is at risk, and knowing which models are affected helps owners and potential buyers make smarter, more confident decisions. If you’re considering a used Porsche or already own one, here’s what you need to know about IMS bearing failure and the vehicles most commonly associated with it.

What Is the IMS Bearing

The IMS (intermediate shaft) is part of the timing system in many Porsche flat-six engines. It supports a shaft that helps drive the camshafts. The shaft itself is durable, but the bearing that supports it can fail over time due to lack of lubrication or metal fatigue.

When the IMS bearing fails, it can throw off the engine’s timing and release metal debris into the oil system. In many cases, it leads to complete engine failure—often without much warning. That’s why the IMS issue is taken seriously and why many Porsche specialists recommend preventative maintenance or upgrades.

Porsche Models at Risk for IMS Bearing Issues

The IMS bearing issue is mainly associated with certain Porsche models built between the late 1990s and mid-2000s. Here are the most commonly affected:

1997–2008 Porsche 986/987 Boxster

First- and second-generation Boxsters with the 2.5L, 2.7L, and 3.2L engines are known to be vulnerable. The early models (1997–1999) had a dual-row IMS bearing that was more robust but could still fail. From 2000 to 2005, Porsche switched to a single-row bearing with a higher failure rate. Some 2006–2008 models may also be affected depending on the engine build date.

1999–2008 Porsche 996 and early 997 Carrera (911)

These models share the same M96 and early M97 engines used in the Boxsters. The 996 generation is particularly known for its IMS concerns, especially between model years 2000 and 2005. Early 997 models (2005–2008) started phasing in redesigned engines with larger, non-serviceable IMS bearings, which have a much lower failure rate but still carry some risk in rare cases.

Important Clarification

The IMS issue does not affect turbocharged, GT2, GT3, and most 997.2 and later Porsche models. These vehicles use a different engine design (often based on the Metzger engine) and don’t rely on the same IMS configuration.

Symptoms of a Failing IMS Bearing

Unfortunately, IMS bearing failure often happens without clear warning. However, there are a few signs that may suggest trouble:

• Metallic shavings in the oil filter or oil pan during an oil change
• Engine knocking or ticking sounds near the rear of the engine
• Sudden engine misfire or stalling
• Check engine light (though not always triggered by bearing issues)

Routine oil analysis and careful inspection during oil changes are key to catching early signs before failure occurs.

How To Take Care Of The Issue

There are several ways to address the IMS bearing issue for affected models. One option is to replace the original bearing with an upgraded version that offers improved lubrication and durability. These replacements are often done during a clutch replacement since both jobs require transmission removal, saving on labor costs.

There are also retrofit kits that allow for external oil feed lines to keep the bearing lubricated, or ceramic hybrid bearings that are less prone to wear. While no solution is 100% bulletproof, upgrading the bearing significantly reduces the risk of failure.

If you're buying a used Porsche from the affected years, ask for documentation on IMS bearing replacement. If there's no record, factor the cost of the upgrade into your decision.

Eurozone Motors – Porsche Service You Can Trust in Burbank, CA

At Eurozone Motors in Burbank, we’ve worked on countless Porsche vehicles and understand the details that matter most to owners. Whether you’re concerned about IMS bearing failure, need an inspection before buying a used Porsche, or want to schedule an upgrade for peace of mind, our team is here to help. Come see us for expert care that keeps your Porsche running strong, mile after mile.