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So my understanding is they went to the 5w-40 (or whatever) oil to help flow through the wet clutch. But if the 5w rating is leading to catastrophic engine failure why are many of us not experiencing that? Just asking.
 

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As i said, this is the initial cold start and driving. If driving off with the engine seconds after starting it you will cause wear. Many people do so. Police often have to due the nature of their job.

A 20w50 will always be thicker, cold or warm, and will thus hold lubricating film longer.

I got this info from a fellow clubmember that works at swedens bmw headquarters.

The findings of the problem and solution came from known swedish mc repair shop (builds and races bikes), they were contacted by bmw and the police to help, and they did, conrod 4 bearings, after going through several engines. Change in oil and the problem went away.

They never blew an engine after that despite using the bikes in the same way.
 

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Thanks Mattias, good to know.

I suspect Swedens tempratures are a tad colder than Irelands, but just a reminder to let the bike warm up a bit more before either riding off or bringing the revs up.

Taken from
The New 4-Cylinder Engine in the BMW K 1200 S
Author(s): Wolfgang Nehse and Manfred Strohe
Source: SAE Transactions, Vol. 113, Section 3: JOURNAL OF ENGINES (2004), pp. 1816-1827
Published by: SAE International
Stable URL: https://www.jstor.org/stable/44723639

"The main bearings without groove are supplied via a bore from the central pressure oil pipe. This results in an extremely narrow construction and thus optimised rigidi- ty in the crankshaft. For the supply of the connecting rod bearings, pressure oil is fed into the crankshaft at centre left. Due to the fact that the oil flow does not counter the centrifugal force, the oil pressure can be set much lower, which positively influences the oil volume flow and also splash losses. Distribution is effected by an oil channel which runs within the crankshaft. The end of this oil channel in the area of the fourth main bearing is closed by a calibrated jet in order to guarantee optimum ventilation. This enables the air taken in with the oil to escape into the crankcase. Even when the oil channels are not filled, the period from engine start to generation of a constant oil pressure is thus reduced from approx. 90 sec with closed jet to an uncritical 5 sec"

So it would make sense if you routinely start the bike from cold, hop on it and tear away, the fourth conrod bearing would get oil last. Looks like it is a "critical" 5 sec after all.
 

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two K1300S bikes, S1000R & Vespa 150 Primavera clown paint job
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Just to confuse things more, in 2010 BMW added a tooth to the oil pump drive sprocket that increased oil pressure.
11 41 8 520 232​
OIL PUMP SPROCKET - Z=26 (from 09/10)​
 

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Just to confuse things more, in 2010 BMW added a tooth to the oil pump drive sprocket that increased oil pressure.
11 41 8 520 232​
OIL PUMP SPROCKET - Z=26 (from 09/10)​
And in 2011 they fitted the K1600 4,5bar oilpump if i remember correct?
 

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I think the extra tooth was to spin the pump faster and it raised the pressure by 1 bar. This might be what your thinking.
The K1600 oil pump is gear driven and looks way different.
 
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A 20w50 will always be thicker, cold or warm, and will thus hold lubricating film longer.
This isn’t true. A 20w50 oil will have the same viscosity as a 5w50 oil at operating temperature.

Oil is always thicker when cold. Within the context of your explanation, a 20w50 oil might not drain as quickly/completely as say a 5w50 oil or 10w40 oil, leaving a nice film on piston 4.

It’s an interesting solution, given the cold climate of sweden. I wonder if the contracted mc repair shop considered getting a very low weight oil (say 0w40) to allow faster pumping action to reach piston 4.

I wonder if this piston 4 plague applies to warm climates as well, where the oil doesn't have that viscosity that a cold swedish engine might.

Actually viscosity and film strength are two separate things anyway.
 

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This isn’t true. A 20w50 oil will have the same viscosity as a 5w50 oil at operating temperature.

Oil is always thicker when cold. Within the context of your explanation, a 20w50 oil might not drain as quickly/completely as say a 5w50 oil or 10w40 oil, leaving a nice film on piston 4.

It’s an interesting solution, given the cold climate of sweden. I wonder if the contracted mc repair shop considered getting a very low weight oil (say 0w40) to allow faster pumping action to reach piston 4.

I wonder if this piston 4 plague applies to warm climates as well, where the oil doesn't have that viscosity that a cold swedish engine might.

Actually viscosity and film strength are two separate things anyway.
I was comparing to a 5/10w40......which is what manual says and the engines blew with.

And he recommended 20w50 7100 motul as it holds lubricating film longer. It worked, in real life, not in theory, R E A L life, no engines blown for 9 years additional service of the model under the same circumstances the engines failed with bmw recommended oil. It worked. Not going to argue on this, it worked.
 

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It would be nice to know if this translates well into climates other than Sweden. OP, did you often start running your bike as soon as it started?
 

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I’ve always started my bike, then put my helmet on. That give time for oil to flow and then I took it easy for the first couple miles to let the engine warm up. Did a few hundred thousand miles on three bikes in Southern California like this before I got my K1300S. Bought a 2014 new in November of 2013 and put about 23k miles on it before moved back to NJ on the bike. Didn’t own a car the entire time I lived in SoCal. Rode everyday and rode hard. It was a rare day I didn’t break 100 mph getting on the freeway and at any other opportunity where I wasn’t lane splitting.

anyway, it seems to me the police bikes that had the blowups like this one were more likely caused by wear due to shutting the bike off when hot, letting it sit long enough that the oil all drain out of the bearings and such, then starting and blasting off at heavy throttle as cops are prone to do. I don’t see the cold starts being the issue. It’s the hot start after sitting for 10-15 minutes or more and leaving immediately accelerating hard to high speed.
 

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^ ^

!!!!


That’s probably it. Bike is hot, oil drains down when hot, bike is started and immediately full sent, the slippery hot oil has no film strength, con-rod explodes.

This really is unique to police who probably sit at the side of the road waiting to catch someone innocently speeding and then immediately getting their adrenaline fix chasing after them, motorcycle engine be damned.

OP needs to chime in if this sounds like a possibility.
 

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In a 10w-40 the 10w bit (W = winter) means that the oil must have a certain maximum viscosity/flow at low temperature. The lower the "W" number the better the oil's cold temperature/cold start performance.

‘Oil is always thicker when cold.’
The 40 in a 10w-40 simply means that the oil must fall within certain viscosity limits at 100°C. . Once again the lower the number, the thinner the oil: a 30 oil is thinner than a 40 oil at 100°C etc. This means Fried Chicken that at colder temperatures the oil acts like a thinner oil to quickly lubricate the engine while at operating temperatures additives cause the oil ‘thicken’.

That’s probably it. Bike is hot, oil drains down when hot, bike is started and immediately full sent, the slippery hot oil has no film strength, con-rod explodes.’
I remember tests being done where cars were drained of oil and drove a number of laps around a race track at normal speeds with no damaged done to the engines so I don’t think that turning a bike off and Having the oil drain, having no film strength is even remotely possible. If this were so all engines would be toast after numerous cold starts with no oil remaining on the cylinder bores.
 

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Mattias I disagree with this statement as well
‘As i said, this is the initial cold start and driving. If driving off with the engine seconds after starting it you will cause wear. Many people do so. Police often have to due the nature of their job.’

This from the net
The common notion during winter is that one should let his car be idle in the cold to warm up the engine.
This is completely and utterly wrong based on reliable sources. Not only are you putting your car under harsh winter conditions, you’re doing more harm than good, too, because of this myth that it should be warmed up.
According to former drag racer Stephen Ciatti, who also has a PhD in mechanical engineering from the University of Wisconsin-Madison, said that idling one’s car not only wastes fuel, but also strips oil from the critical components such as cylinders and pistons.
An internal combustion engine, like the one found under the hood of a Mercedes-Benz, works by using pistons to compress air and vaporized fuel within a cylinder. This mixture of air and fuel is ignited to create a combustion event, which then results to a little explosion that powers the engine.
When your engine is cold, the fuel compensates by creating the right air-and-fuel ratio for the combustion engine. In fact, engine with electronic fuel injection have sensors that instructs the engine to pump more fuel into the mixture.
When you let your car be idle, it puts more gasoline into the combustion chamber, which can then get on the cylinder walls. And because gasoline is an “outstanding solvent,” it can wash off oil from the walls when the engine runs for an extended period of time.
Stripping away the lubricating oil from your engine’s important components can reduce their life. The best way to warm up your Mercedes engine is to drive it. When it reaches the temperature of 40 degrees Fahrenheit, it can switch back to a normal air to fuel ratio.


I’m no expert of course and have to rely on those that are😁
 

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In a 10w-40 the 10w bit (W = winter) means that the oil must have a certain maximum viscosity/flow at low temperature. The lower the "W" number the better the oil's cold temperature/cold start performance.

‘Oil is always thicker when cold.’
The 40 in a 10w-40 simply means that the oil must fall within certain viscosity limits at 100°C. . Once again the lower the number, the thinner the oil: a 30 oil is thinner than a 40 oil at 100°C etc. This means Fried Chicken that at colder temperatures the oil acts like a thinner oil to quickly lubricate the engine while at operating temperatures additives cause the oil ‘thicken’.

That’s probably it. Bike is hot, oil drains down when hot, bike is started and immediately full sent, the slippery hot oil has no film strength, con-rod explodes.’
I remember tests being done where cars were drained of oil and drove a number of laps around a race track at normal speeds with no damaged done to the engines so I don’t think that turning a bike off and Having the oil drain, having no film strength is even remotely possible. If this were so all engines would be toast after numerous cold starts with no oil remaining on the cylinder bores.
The W means that at low temperatures (winter), the oil behaves (has the viscosity) like a standard oil (i.e. SAE 10 in the case of 10w-40) would behave. Once it heats up it behaves like a “normal” (standard) oil would (i.e. SAE 40 in the case of 10w-40). The oil is shapeshifting. A shapeshifting oil 🧐. Incidentally this is exactly how it does it on a molecular level. The molecules change conformation in response to temperature.

My understanding is this is done to make the cold and hot viscosities closer to one another, thereby tightening potential tolerances for other components (i.e. the engine or piston).

There is a caveat
Putting a thinner oil (i.e. going from 15w-50 to 10w-40) has the effect of the oil running off components faster, thereby leaving them vulnerable in a sense.

Now flip it around.

The swedish police would sit with their engines at idle, getting super hot. This would make the oil less viscous, and have it drain off the components (even with the engine running). Suddenly gunning it will increase the oil flow, but not fast enough, so suddenly these components that have had super hot oil don’t have a thin protective film, and will be subject to more wear than would happen to a normal rider under normal circumstances.

Switching to 15w-50 oil would solve that. The super hot oil wouldn’t get as thin as the 10w-40 would. A nice film is able to form and not run off, so when the police guy guns it, the added stresses don’t cause the engine to jihad.
 

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I agree that thicker oil takes longer to drain off but thinner oil does not totally drain off leaving the components dry. I also don’t understand how a water cooled thermostatically controlled bike can get ‘super hot’! I idle attraffic lights in 40 deg C (104 deg F) The fan is on a lot longer but the bike stays within limits.
 

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I agree that thicker oil takes longer to drain off but thinner oil does not totally drain off leaving the components dry. I also don’t understand how a water cooled thermostatically controlled bike can get ‘super hot’! I idle attraffic lights in 40 deg C (104 deg F) The fan is on a lot longer but the bike stays within limits.
Mine sits one or two bars above middle when idling for a long time. Every engine does this. Water cooling doesn’t reach every single part.
 

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Any update on the outcome? Cause? Conclusion? What happened ?
Never heard of something like this happening before and can only think that there’s more to this story than meets the eye! dry sump engine that maybe was starved of oil ?
Did someone do the first service and forgot to add oil? It happens!
OP went dark on this tread!?
 

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Hi all. I am new to this forum, but was immediately drawn to this thread because I experienced the exact same thing. Riding on the left lane of the motorway, heard a big "boom", experienced a power drop, saw a huge grey cloud appearing in my mirrors... Made it to the emergency lane, to see oil pissing out. Later diagnosis showed the same thing: same conrod "poking out". No discoloring to indicate oil shortage or anything, seems like one conrod bolt went AWOL and then the other sheared off. This was for a 2009 K1300s with about 55k km. Had been riding for several hours already, probably had done 300km that day (and was still 400km from home...). So this definitely supports the "starting hot" hypothesis in the thread most.
 
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