IMS Failure is not a Myth.

[gregwils]

There are really two issues here. First, the probability it will occur. Second, the consequence if it does. The first is highly debatable. The second is not - cataclysmic failure.

The scenario here is very similar to the old air-cooled days, hydraulic tensioners were failing and destroying SC motors. Porsche introduced pressure fed tensioners which did address the issue. The first thing people (should) check when buying an SC is whether or not the tensioners have been upgraded to pressure fed. Ironically, the cost to have it done is pretty close to an IMS upgrade. No one wants to spend the money, but if you look at as an insurance policy, it really is a wise investment. My $.02.

[NoGaBiker]

Originally Posted by gregwils

There are really two issues here. First, the probability it will occur. Second, the consequence if it does. The first is highly debatable. The second is not - cataclysmic failure.

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I suspect it's only catastrophic, not cataclysmic.

[mts]

Originally Posted by gregwils

There are really two issues here. First, the probability it will occur. Second, the consequence if it does. The first is highly debatable. The second is not - cataclysmic failure.

No one wants to spend the money, but if you look at as an insurance policy, it really is a wise investment. My $.02.

Good point. A big issue is if you happen to be someone in the 2%-20%, however you define the failure rate, you are looking at big $$ to get the car back on the road. As these cars get older, a good fix after a failure could in excess of what the car is worth. That is a terrible result.

My IMS did fail at around 20k miles. Porsche replaced the motor under goodwill, but since the new motor was unable to have the IMS upgraded at a reasonable cost each time I did the clutch (as recommended by LN with their bearing), I sold the car.

Whether 1%, 2% or 20%, the failure rate is unacceptably high, especially on low mileage cars and I can't think of another 1998-later car of any brand that has a catastrophic failure rate anywhere close to the M96 cars.