well … the physics of it is that they spin when the friction between the moving bits and the bearing is greater than the forces keeping the bearing in place. usual suspect for this would be oil starvation.
But the interesting thing, from Ovalautos various posts is that even tabbed ones move. Notice it's "move" he uses and not "spin".
Is the implication they move sideways ? or is he saying they rotate a bit rather than spin freely ? (which might be how some would interpret "spin" )
I was also surprised to learn that in some racing engines, they are screwed in place !! I though that would not work as the screw would expand and score the crank … but would that matter ? the scored section would simply hold more oil, would it not ?.
Dean
====================================
2011 D4 XS - OBD port protection, RLD spare wheel protector, All LED interiors lights, Timed Climate enabled, iiD tool paired.
2011 D4 Landmark - Stolen from same dealer before I paid for it
2011 D4 GS - Stolen whilst at dealer ... All LED interiors lights, DRLs, Spare Wheel protector.
1996 300Tdi - Eaten by tin worms
15th Jan 2019 10:17 pm
MrBrain
Member Since: 12 Mar 2014
Location: bucks
Posts: 471
Has anybody considered an additional electric oil pump? So that pressure is up before the engine starts? I get a vague feeling that the issue is too many short cold journeys.
15th Jan 2019 10:30 pm
Andy500
Member Since: 27 Aug 2018
Location: Cheshire
Posts: 228
I was pondering about this the other day following Ovalautos post re the number they will see in a year. Does anybody know if there is anything common about the operating conditions that the engine has been/is under when the failure occurs I.e is it always when the engine is cold that it lets go or does it typically happen well in to a journey when the engine and fluids are all well at operating temps?
Just be interesting to know the conditions when failure occurred to see if there is any common theme?
15th Jan 2019 10:34 pm
MrBrain
Member Since: 12 Mar 2014
Location: bucks
Posts: 471
I know of two that occurred. Both on start-up. But I bet its not that clear really.
15th Jan 2019 10:41 pm
Andy500
Member Since: 27 Aug 2018
Location: Cheshire
Posts: 228
Do you know if they had both been stood for a while or was it like day 1 ok next day kaput!
15th Jan 2019 10:46 pm
MrBrain
Member Since: 12 Mar 2014
Location: bucks
Posts: 471
Both on restarts during a normal day's use.
15th Jan 2019 11:08 pm
DSL Keeper of the wheelie bin
Member Since: 11 May 2006
Location: Off again! :-)
Posts: 72740
Mine packed up when engine was warm and had been driven a couple of hundred miles tootling around N Lofotens (sp?) that day. When it’s quitting time they just quit.
15th Jan 2019 11:21 pm
MrBrain
Member Since: 12 Mar 2014
Location: bucks
Posts: 471
So you were driving and suddenly bang bang clatter?
one of the oddities of your case was that we don't actually know what failed … it was just it happened in a scenario that made it not financially viable to ever find out.
might have been a large twig caught in the serpentine belt for all you kow !
( I say that because there was once a famous story of exactly that happening with a Rolls-Royce ... ended up being "taxied" to Cornwall (IIRC ) because the AA/RAC man was too frightened to risk damaging an expensive car he had no knowledge of that he had the car/owner taken home … owner was quoted as being delighted the problem wasn't serious in the end AND he'd saved a fortune on fuel )..
Dean
====================================
2011 D4 XS - OBD port protection, RLD spare wheel protector, All LED interiors lights, Timed Climate enabled, iiD tool paired.
2011 D4 Landmark - Stolen from same dealer before I paid for it
2011 D4 GS - Stolen whilst at dealer ... All LED interiors lights, DRLs, Spare Wheel protector.
1996 300Tdi - Eaten by tin worms
15th Jan 2019 11:31 pm
DSL Keeper of the wheelie bin
Member Since: 11 May 2006
Location: Off again! :-)
Posts: 72740
You implying I was beating the car Fawlty Towers style?
Have you noticed SWMBO is on holiday with you? Can't carry on like on your normal roadtrips you know! .
Dean
====================================
2011 D4 XS - OBD port protection, RLD spare wheel protector, All LED interiors lights, Timed Climate enabled, iiD tool paired.
2011 D4 Landmark - Stolen from same dealer before I paid for it
2011 D4 GS - Stolen whilst at dealer ... All LED interiors lights, DRLs, Spare Wheel protector.
1996 300Tdi - Eaten by tin worms
15th Jan 2019 11:46 pm
DSL Keeper of the wheelie bin
Member Since: 11 May 2006
Location: Off again! :-)
Posts: 72740
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