[PaulE]

I bought a 2003 S new and didn’t know about the IMSB. About 6 years and 42,000 miles into it I learned about it and had the LN single row pro installed. The original IMSB was still fine and I still have it. A year ago at 77,500 miles the LN unit failed. In my case, everything was fine right until it wasn’t. It was caught before any major damage occurred. In terms of failure parts my rebuild only required a new IMS, one broken timing chain paddle and the oil pump internals. The crank, block, cylinder heads, rods and pistons were all fine but I decided to have it increased to a 3.6 for the rebuild. The oil cooler and hydraulic lifters were also replaced as a precaution and all the other usual rebuild parts and gaskets went into it.

So my point if there is one is that the IMSB is fine until it isn’t and if you’re lucky when it goes the engine will be rebuildable.