On Dec 6, 8:30*pm, The Natural Philosopher
wrote:
I've not seen one snap at 40k, but had two (both vauxhall) go at the
sort of 70k mark.

A few Volvo used to have a zero tolerance policy linked to the
odometer, if you went as little as 200 miles over you got bitten by a
very large bill re interference engine.

On some engines if you bend valves you also damage bearings, if they
are not replaced they fail some time later. Relative who believes cars
are "self maintaining" did the valves, got a backstreet place to do it
to save £120 (!) and in the words of alfa romeo UK "if the bearings
are not replaced we guarantee the engine will fail within 12,000
miles". They were right. It did. Spectacularly on a motorway.

No wonder they want electric cars... computer controlled accident
avoidance... programmers saying "now why did it do that...".