For several years Ruby's engine had been difficult to start, especially on cold days. This is typical of a diesel engine that is suffering from a lack of compression. This is usually caused by the piston rings failing to grip the cylinder liners sufficiently, which means that the compressed air escapes down the cylinder and into the crank case.

Ruby has also suffered from heavy breathing i.e. steam & exhaust gases coming out of the crank-case breather pipe. This was caused by coolant water getting into the crank case, from two broken injector sleeves, warn piston rings & a crack in the engine block itself.