[thstone]

If you get an alert, you're supposed to call and get a recommendation on how to proceed. Most likely this will be an evaluation by a skilled professional to determine what might be failing.

There are about 22 known modes of failure in the M96 engine and the IMSB is only 1 of the 22 so it would be important to find the root cause of the Guardian alert.

The costs of a re-build before a catastrophic engine failure are likely to be less than after the engine detonates however the costs are variable based on the shop and the parts that the shop recommends replacing.

Do a search on this site and you'll find lots of discussion on the IMSB and engine replacement options.