I have seen the 6 cylinder #3 and # 4 rod bearings go bad on 2 separate occasions. Both engines were in the 120K mileage range and both had routine maintenance records. I was not sure if it was oil flow problem or just a bearing failure, it did ruin the crankshaft in both cases. The only other issues I have encountered were with the variable valve timing circuit. The engine would have a code and the sensor would test fine. I have seen more than one sensor replaced only to have the code come back within a 1000 miles. I believe a good block flush may have restored oil control to the sensor and cleared the problem. As I was not the Tech working on the engine they just kept changing the sensor, same problem each time.
