Looks like my previous thread was closed, but I wanted to update everyone on what's going on with my blown engine. Took the car to an independent dealer and they quickly established that this wasn't a lower end failure like Mazda claimed. Holes were through the side and upper portions of the block; pan was intact. We just pulled the head today and the bottom half of the rod is still connected to the crankshaft and rotates smoothly and freely. The head is in good shape, but the exhaust valves are stuck slightly open (damaged by flying piston bits?). Out of the debris that we pulled out of the cylinder we saw two large pieces of the piston (a left and right half). I can't say exactly what happened without a complete failure analysis, but from the way the separated surfaces appear (grainy on the surfaces that weren't subsequently impacted by debris) it looks like the piston failed at the wrist pin. This would have allowed the piston to flop about in the cylinder and wedge between the rod and cylinder causing it to fail as well. Of course the rod could have failed first, but I doubt it based on how I drive the car (I don't wring it out) and what was going on at the time (lugging 5th at 55 mph on the freeway as we started speeding up again). This failure seems to be in line with what I had originally explained to Mazda where it did it's usual "detonation" like stutter which would have placed tremendous stress on the thin, aluminum piston. However, when it did it this time it was a lot louder than it had been ever before and the failure occurred immediately after I started to roll back into the throttle.
So long story short, I've contacted the Mazda dealership and told them that this wasn't a lower end failure like they thought and from the condition of the piston it does not appear to be oiling related (no overtemp discoloration). So even though I'm missing a few of my oil change receipts, hopefully they will be reasonable in how they handle this from here on out. I just wish they wouldn't have jumped to conclusions in the beginning and forced me to pay for all of this work (along with the purchase of a $4,000 junkyard engine).
Stay tuned...
So long story short, I've contacted the Mazda dealership and told them that this wasn't a lower end failure like they thought and from the condition of the piston it does not appear to be oiling related (no overtemp discoloration). So even though I'm missing a few of my oil change receipts, hopefully they will be reasonable in how they handle this from here on out. I just wish they wouldn't have jumped to conclusions in the beginning and forced me to pay for all of this work (along with the purchase of a $4,000 junkyard engine).
Stay tuned...
