Situations reported on this and other forums run the gamut. Water pump is not usually too bad - it will leak and you should at least start seeing a drop in coolant level if not coolant on the ground (sometimes it leaks strait back into the valley of the engine instead of onto the ground). But, the crossovers often seem to just let go completely, causing a near instantaneous loss of coolant to the engine. I’ve read many stories of this happening (usually on the highway it seems), and by the time the person notices the coolant light and pulls over, it’s too late. Dealer tells them 15-20K for new engine.

What’s even worse is that the degrading coolant pipes often show zero leak on pressure testing. On my car, I had definite coolant smell (even the tech noted it), and had it pressure tested three times at two different dealers before the warranty ran out. Passed each time. Once the warranty was up, I just decided to do it myself preventatively and, sure enough, the front crossover was just about to go. That was at 52K on a supercharged model. There are numerous other accounts of people passing pressure tests with degraded pipes. The pipes degrade below the level of the block, so they often don’t start leaking much at all until it gives way completely.