Yeah mine looked fine when I had to do the front cover for a coolant leak. Several months later it exploded in my driveway into several pieces ate the woodruff key and destroyed the front cover. My only saving grace was that it did happen in the driveway and I was able to shut down as soon as it happened. If I had been driving when it happened I would have probably been looking at a full rebuild. If you have the front cover off do the oil pump.

 

X1

Apart from physical routine replacement I reckon oil pressure fluctuations is the only other way. With an accurate analogue or digital oil pressure gauge that incorporates both visual and audible alarms would help immensely. Having said this, catastrophic immediate failure is not predictable but there again it's not predictable on most components. At least OP gauges will give you some chance of saving the engine if recognised and acted upon rapidly.

 

A couple weeks ago I replaced the water pump. Front cover never came off.