Got one big prob with diesel, which it will runaway, usually occurs when the engine is really worn out...
But i not sure this will happen to new modern diesel or not... Last time i read on other forum, there a guy with his common rail mitsubishi diesel runaway on highway... that a 1:18 compression engine if not mistaken

What runaway you're referring to? There are local 320d cars that have clocked over 150k km without any issue apart from replacement of oil sump nut. Go figure.

What causes runaway is for example, a failed turbo seal on the intake side cause the engine oil to leak ... therefore the oil get sucked into the engine via intake stream... Since diesel are heat ignited engine, therefore the oil get suck from the engine will continue to combust... continue to do so until the engine blow itself up because of lubrication starvation...

Wow... this is scary... but I guess this is more of a QC issue.. perhaps 1 in a million units would be the lemon one.

seriously, how many units got this problem ?