This particular OM651 diesel engine failed, but the issue does not appear to be related to its complex, overbuilt construction.
WD-40 is a legendary water displacer, but it isn't a universal fix. Using it on the wrong surface can lead to mechanical ...
In this BS6 era, diesel cars run cleaner, they are more technologically advanced, and at the same time are more complex than ever.
That old engine may be tougher than you think — if you treat it right.