Porsche 986 Boxster
Currently, the best values in used Porsches are the 986 and 996 generation cars. Both the Boxster (986) and 911 (996) offer a good amount of performance with prices of both being south of $20,000. In fact you can find a clean running early Boxster for as low as $5,000.
While the 996 will run you a bit more, you can find clean running early examples of the 911 For under $15,000 and we’ve seen a few as low $10,000. While there are a few things that attribute to these low prices, there is one major reason that they are so affordable, the Intermediate Shaft Bearing (IMS).
The problem stems from a design flaw that results in catastrophic engine failure. 986, 996, 987 and 997 generation cars (911, Cayman and Boxster) use the design and could have the failure. While all can experience the issue, there are some years that have a higher rate of failures. It is also important to note that 911 GT3, GT2 and Turbo models use a different design so they do not have the IMS problem.
The main design flaw is that the IMS Bearing used an enclosed design for the bearing which would seize when the internal grease would break down over time. Because of it being sealed no additional lubrication is available when this happens.
The 1997 – 1999 986 and 996 cars featuring the early M96 engines used a more durable dual bearing design. While these cars can still have IMS Bearing failure, the rate is estimated very low (depending on which statistics you believe the rate is stated as less than 1%).
Some 2000 and 2001 cars also used the double bearing design, but for the most part the 2000-2005 are the most prone to failure. These cars used a single bearing that was not reinforced. Because of this failure rates have been estimated between 7% and 20%, but most agree it is around 10% that fail.
The 2006-2008 models used a single row IMS bearing, but one that was reinforced which reduced the failure rate. The one problem is with these cars is that the engine must be disassembled in order to make any preemptive updates to the bearing. This raises the skill required as well as labor costs for these years.