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Porsche 997: Why the IMS Bearing Issue is Overblown

There are multiple online claims of Porsches suffering of IMS bearing issues, but how much of that is supported with facts? Learn more about this issue here.

By Jerry Perez - May 4, 2015

This article applies to the Porsche Carrera 997 (2005-2006).

Almost all cars produced will have some sort of problem, regardless if they are economy cars or high-end sports cars like the Porsche. In the end, any kind of machine is bound to suffer from a breakdown at some point in its productive lifespan. Porsche has been at the center of a recent controversy due to IMS (intermediate shaft) bearing failure in some 997 production cars, but recent data shows that there may not be as many problems as initially thought. We've done the research and compiled all the proven facts on IMS bearing failure for the 997 model in this article.

IMS Bearing Issues

How IMS Bearings Affect the Engine

The IMS bearing is an internal engine component which plays a major role in making sure other engine parts like the crankshaft and oil pump work as intended. The actual IMS bearings are made up of sealed bearings that contain small roller or beads so the crankshaft can work smoothly on them. If the bearings were to fail, then the parts could get lodged inside the engine and cause anywhere from mild cylinder damage to complete engine failure.

Figure 1. Inner workings of a 997 engine and IMS bearings.

The Facts

According to research and multiple surveys, the results of which were published on Rennlist.com, the IMS bearing issue could be narrowed down to 997 models that were produced in late 2005 and early 2006. Even out of that short time frame, less than 1% of vehicles were affected by IMS bearing failure. So, it's possible that most of the talk and panic found across the Internet may have been blown relatively out of proportion. The various surveys over three years of research have revealed few chronic problems, while showing a couple one-off occurrences that could be attributed to nothing else than simple manufacturer problems. Most 997.1 and 997.2 models are nearly bulletproof, and most senior forum members would be surprised if any engine issues are attributed to IMS bearing failure for these two models.

  • Figure 2. IMS bearings.
  • Figure 3. IMS bearing cover.

Which Models Were Affected?

The IMS bearing issue is a carryover issue from the 996 model. The earlier non-Carrera S 997 models had the same basic engine as the 996, hence, the same issues.

Most late 2005 and early 2006 997 models are included and, as mentioned earlier, a very small percentage of those cars were affected. But if there is doubt in your mind, most experts completely rule out any IMS bearing failure on 2007 and newer 997 models, as some engine components were updated and no incidents have been reported so far. If you happen to be in the market for one, remember that a Porsche CPO warranty could be a good idea, possibly helping you sleep better at night. So far this is not a reason to pass up on your long-awaited Porsche acquisition.

Figure 4. The Porsche 996 experienced some IMS bearing problems.

Preventive Maintenance

It's always hard to recommend a specific set of rules on what to do to prevent IMS bearing failure when there is no confirmed reason to cause the failure to begin with (other than manufacturer defects). Some Porsche experts recommend that if IMS failure is a big worry as an owner, then there are aftermarket bearings that could be installed early in the car's life that may offer protection from a highly unlikely but catastrophic event. These bearings plus installation could cost up to $2,000 and are surely a price fix to a non-existent problem.

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