Porsche IMS Bearing Statistics - What is the Risk of Engine Failure in 911 and Boxster?

What is the risk of Engine failure from IMS (Intermediate Shaft) in the Porsche 911?

The water cooled engine introduced for the Porsche 911 and Boxster in 1998 has become known for engine damage from failure of the IMS - Intermediate Shaft bearing which severely damage the engine of the Porsche 911 (996) or Boxster and can require complete rebuild at very high cost.

As part of a law suit in the USA, figures have been released for the likely risk of IMS Bearing failure on the Porsche 996 engine in different versions of the car. The first 996 (996.1) up to 2001 with the 3.4 litre engine actually has the lower risk at 1% and the later 3.6 litre engine has significantly higher risk of IMS failure at 8%.

Porsche 996.1, 3.4L engine, Years: 1998 to 2001 - 1%
Porsche 996.2, 3.6L engine, Years: 2001 to 2005 - 8%

So according to these figures the 3.4 litre engine in the Porsche 996.1 is 8x LESS likely to suffer an IMS failure than the later 3.6 litre engine from late 2001/2002 onwards.

According to these figures from Porsche 99% of early 996 models have not suffered from IMS failure which is the opposite of the view you would get from reading internet forums!

More details of the Porsche IMS settlement



Porsche IMS Bearing Statistics - What is the Risk of Engine Failure in 911 and Boxster?