MRF Engineering: Rod Bearings, Teardowns, Failures & Replacements. **PICTURE Diary**

[MilehighM3]

Originally Posted by Malek@MRF

Considering many things, the car ran much better with the Mobil1 0W-40 than it did with the Castrol TWS 10W-60 oil.

Until it stopped running, and apparently with authority? Temps and pressure are great specs, but why not send a sample out for testing? Provided there is some oil remaining that could be used. Given that the Mobile will shear down more compared to the Castrol will in extreme conditions, it's worth looking into. Pressure is great, but if the oil isn't where it needs to be, when it needs to be, let's just say things tend to go boom...

[Malek@MRF]

Originally Posted by MilehighM3

Until it stopped running, and apparently with authority? Temps and pressure are great specs, but why not send a sample out for testing? Provided there is some oil remaining that could be used. Given that the Mobile will shear down more compared to the Castrol will in extreme conditions, it's worth looking into. Pressure is great, but if the oil isn't where it needs to be, when it needs to be, let's just say things tend to go boom...

Mobil1 has has more sheer resistance compared to TWS. Here are the sheer resistance values of each for reference.

M1 0W40: 0.8594
TWS: 0.8094

Unfortunately, sending a sample out for a motor that is already done with won't be of any help.

For some trivial information... A lot of the modern M's who's oil temps are consistently at 240*+ on normal operation now run the standard BMW 5W-30 oil, and the N54, N55 cars which consistently run at 250*+ also use BMW 5W-30.

Let's keep this thread on topic, we have enough threads here on oil debate.

[MilehighM3]

Originally Posted by Malek@MRF

For some trivial information... A lot of the modern M's who's oil temps are consistently at 240*+ on normal operation now run the standard BMW 5W-30 oil, and the N54, N55 cars which consistently run at 250*+ also use BMW 5W-30.

Let's keep this thread on topic, we have enough threads here on oil debate.

Speaking of staying on topic, those are also all direct injected turbo cars. Not exactly an apples to apples comparison. Sorry to hear about a failed S65, back on topic now.

[SenorFunkyPants]

Originally Posted by Malek@MRF

Mobil1 has has more sheer resistance compared to TWS. Here are the sheer resistance values of each for reference.

M1 0W40: 0.8594
TWS: 0.8094

HTHS Mobil 1 0W40 is 3.8
HTHS Edge pro 10W60 is 5.2
Higher is better.

[chris719]

HTHS is not the same thing as shear resistance. The oil with the larger viscosity spread will almost always shear faster due to the increased use of VII polymers.

The film strength (HTHS) of the higher viscosity oil is stronger, obviously.

[SenorFunkyPants]

Castrols 10W60 typically shears down to a low 50W.
Mobil1 0W40 typically shears down to a mid 30W.
Whatever benefit that may provide is more than offset by having a lower film strength (the point I was making).

[aussiem3]

Originally Posted by chris719

The film strength (HTHS) of the higher viscosity oil is stronger, obviously.

Isn't this what you want? protection

[chris719]

There has to be a balance. Thicker oil will not flow as well at startup. Even 0w-40 is not as thin on startup as 0w-20 despite the same 0 SAE cold rating. Also, clearances and the oil pump have to accommodate the thicker oil. Have to account for temperature too, so it depends on usage.

As thick as you need but no thicker is the ideal I suppose.

What that is for the S65 is up for debate. I am inclined to think 0w-40 is fine if you don't track the car and may be preferable if you are in a cold climate and make frequent short trips. I also don't know that I believe the 10w-60 is responsible for the bearing issues. What is striking on teardown is that there are often one or two cylinders much worse than the rest. What no one has been able to determine, to my knowledge, is if these were "loose" or "tight". The other question is if the bearing wear is occurring when the engine is cold or when it's driven at high RPM after being warmed up.

[SenorFunkyPants]

Originally Posted by chris719

What that is for the S65 is up for debate. I am inclined to think 0w-40 is fine if you don't track the car and may be preferable if you are in a cold climate and make frequent short trips. I also don't know that I believe the 10w-60 is responsible for the bearing issues. What is striking on teardown is that there are often one or two cylinders much worse than the rest. What no one has been able to determine, to my knowledge, is if these were "loose" or "tight".

+1

I believe that BMW were obliged to use the 10W60 for the S65. Its a legacy engine design, it was way cheaper to derive the S65 engine from the S85 than use a clean sheet design. BMW addressed the main areas that had caused problems with the S85 (the high pressure Vanos and the anti knock system and evolved the oil lubrication system) but were stuck with the internal components as they were. Its entirely logical to believe that if the data produced from long term S65 engine testing and failed S85 engine strip downs indicated that a thinner oil would have been a benefit then BMW would have spec'ed it. There has been an industry wide shift to engine designs that use ever lighter engine oils - (Ford make a turbo engine with a higher specific output/ltr than the M3 and it uses a 20w oil) - for better economy and higher power but if you are stuck with an old design then you have to go with the oil weight that the design calls for.

Originally Posted by chris719

The other question is if the bearing wear is occurring when the engine is cold or when it's driven at high RPM after being warmed up.

I reckon if cold start wear was a problem then failures in the NE of the USA would show a higher rate than it does (its lower than the average) so I'm leaning towards high temp high revs as the being more damaging.

[chris719]

Can anyone with experience say if this looks like cavitation erosion on the bearings? I am also curious as to why the edges are normally spared.

[pbonsalb]

Some of mine showed copper on the edges. In fact, that was the only area in which I can see any copper.

[Malek@MRF]

Hello, I hope everyone is enjoying their holidays and the new year is upon us.

I will keep this straight to the point as much as possible. Here we have an engine I have torn down for a client. The engines history is as follows:

• 2013 BMW M3 Coupe
• 39,500 miles on engine + chassis
• 38,000 miles SUPERCHARGED via ESS VT2-625
  
• 33,500 miles with VAC Coated Rod Bearings + ARP Connecting Rod bolts
• Engine Oil Specification 10W-60 every 5000 Miles. At 10,000 miles, the engine was only filled with Liqui Moly 10W-60, not Castrol TWS and every oil service thereafter every 5000 miles.
  

The engine was fully broken down, organized and fully checked. No flaws could be found. To my surprise was the condition of the rod bearings, and the crankshaft. It is widely known that the VAC Coated OEM bearings REDUCE bearing clearance due to the coating adding thickness to the bearing shell. For those who are wondering, the bearings are not coated by VAC, they are done by Calico with their CT-1 coating process.


Calico's description:


"CT-1 Dry Film Lubricant coating is applied as a spray process. Different surface preparation methods appropriate for the substrates will be used prior to the coating process. Coating thickness is varied to suit the application. Typical coating thickness for engine bearings is 0.00025" to 0.00030" inch (6 to 7.5 microns)."



What was found was not indicative of what we commonly know, or expected, what was found was shocking. Why shocking? The OEM bearings when they were done, were already exhibiting rapid, accelerated wear.


Image #1: One of the OEM bearings that show very abnormal wear at 6000 miles.





Remaining images: Show bearing wear for all shows, organized from Rod 1-8. Also shown, the condition of the crankshaft. As shown, the bearings have no wear.













I have brought up this topic in the past, and have spoken about it to BMRLVR, Kawasaki00 about the possibility that these engine failures could be subject to assembly error, fastener defect or outright an engineering oversight on what the torque on the OEM stretch bolts should be. It is possible for a bearing cap to be over-torqued and tighten bearing clearances, enough to induce failure from the engine being assembled too tight.

Just throwing a curve ball into the mix... Valuable input and thoughts are welcome!

Happy Holidays,

Malek@MRF

[douglee25]

Very interesting.

[Malek@MRF]

Thread Update:

I have finalized full dis-assembly of my own engine. The results are poor.

Cylinder 1+2 suffered rod bearing failure. However, first MAIN journal has also failed. As a result, the block is cracked at the oil hole.

Cylinder 5+6 rod bolts under-torqued.

Every connecting rod bearing has very odd debris deposits visible in the pictures. The only 2 bearings that this cannot be verified is bearing 1+2, as the bearing is destroyed as well as the crankshaft.

Engine/Vehicle History:

• 2011 BMW M3 (E92)
• 6-Speed Manual Transmission
• Engine is stock aside from exhaust system
• Mileage 39,xxx
• Oil Changes intervals every 5000 miles
• Stock OE BMW Rod Bearings + Stock OE BMW connecting rod bolts

[BPMSport]

Wow.. That does not look good.. Especially with 40k..

[///M Power-Belgium]

WTF !!! Is going on with our engines ?!?!

1-Stock engine 2011 with only 39K on it ,and had every 5K oil change !
2-Bearing failures ,bearings from cylinder 1+2 are looking like a "dinosaur" has chewed on them !
3-Engine block is cracked !
4-Crankshaft is damaged !

Malek if I may ask you...Did you heard any ticking or rattle noises ?
And what oil...Brand/Type was used ?
Blackstone report ?
Questions are for my database...
Thanks in advance...

[Malek@MRF]

Originally Posted by ///M Power-Belgium

WTF !!! Is going on with our engines ?!?!

1-Stock engine 2011 with only 39K on it ,and had every 5K oil change !
2-Bearing failures ,bearings from cylinder 1+2 are looking like a "dinosaur" has chewed on them !
3-Engine block is cracked !
4-Crankshaft is damaged !

Malek if I may ask you...Did you heard any ticking or rattle noises ?
And what oil...Brand/Type was used ?
Blackstone report ?
Questions are for my database...
Thanks in advance...

I will gladly share my information for your database.

-The engine never made any rattling or ticking noises when it failed. It simply failed, lost a lot of power and began to stall. Immediately upon feeling this, the car was turned off, and towed home to never be started again. This is probably what saved a rod from coming through the side of the block.

-Oil analysis was never really considered much for this car except for once and it was totally normal. It's a 2011 and doesn't have the lead based bearings so any pre-detection would have been difficult/impossible.

-The car was considered an "under driven vehicle" by BMW, so the oil services occured by them at 10k, 20k. At 30k the car got Liqui-Moly 10W-60. A service with the same TWS oil was done at 5k, 15k, 25k. For a short stint the car was on Mobil1 0W-40 after 30k, oil temps were lower than stock.

This should NOT happen to an engine with 39k that has been religiously maintained. It is also stock with an exhaust system only. Stock air filter, stock spark plugs, stock pulleys and belts.

[Beedub]

wow bmw.... just wow.......

s54, s85, s65, all the same.... its like they never learned......

[NELSON.MLGB]

I found most of the cars that have the bearing issue are with MT, is it true?

[///M Power-Belgium]

Originally Posted by Malek@MRF

I will gladly share my information for your database.

-The engine never made any rattling or ticking noises when it failed. It simply failed, lost a lot of power and began to stall. Immediately upon feeling this, the car was turned off, and towed home to never be started again. This is probably what saved a rod from coming through the side of the block.

-Oil analysis was never really considered much for this car except for once and it was totally normal. It's a 2011 and doesn't have the lead based bearings so any pre-detection would have been difficult/impossible.

-The car was considered an "under driven vehicle" by BMW, so the oil services occured by them at 10k, 20k. At 30k the car got Liqui-Moly 10W-60. A service with the same TWS oil was done at 5k, 15k, 25k. For a short stint the car was on Mobil1 0W-40 after 30k, oil temps were lower than stock.

This should NOT happen to an engine with 39k that has been religiously maintained. It is also stock with an exhaust system only. Stock air filter, stock spark plugs, stock pulleys and belts.

Thank you for the information and feel realy sorry about your luck .
Personal I think there must be something wrong with our bearings from when our S65 left the factory in Germany !
Few days ago I saw bearings with 86K on it...and guess what ?
They looked realy good and the guy could have run 150K with bearings in that condition => http://www.m3post.com/forums/showthr...0#post17156950
It seems or they are good or realy bad... and that from out of the factory... incorrect size or ...incorrect fitting of the bearings,and that causes the wear on the bearings ?
No matter what oil is used,stock engine or not...when they have to fail they fail ,the proof is that I saw bearing failure on a S65 built end of 2013 with only 6.7 K miles on it !
So again for me personal it's a factory problem ..it's more like.. some are lucky and other are not ,it's almost a lottery !

[aussiem3]

This is serious stuff

[bigjae1976]

Originally Posted by Malek@MRF

I will gladly share my information for your database.

-The engine never made any rattling or ticking noises when it failed. It simply failed, lost a lot of power and began to stall. Immediately upon feeling this, the car was turned off, and towed home to never be started again. This is probably what saved a rod from coming through the side of the block.

-Oil analysis was never really considered much for this car except for once and it was totally normal. It's a 2011 and doesn't have the lead based bearings so any pre-detection would have been difficult/impossible.

-The car was considered an "under driven vehicle" by BMW, so the oil services occured by them at 10k, 20k. At 30k the car got Liqui-Moly 10W-60. A service with the same TWS oil was done at 5k, 15k, 25k. For a short stint the car was on Mobil1 0W-40 after 30k, oil temps were lower than stock.

This should NOT happen to an engine with 39k that has been religiously maintained. It is also stock with an exhaust system only. Stock air filter, stock spark plugs, stock pulleys and belts.

That's a good point because I have rarely changed my oil based on mileage since I rarely drive my M3 more than 5k in 6 months. I normally change my oil every 6 months.

I find the first pic of the pitted bearings interesting...maybe there is some correlation between long time intervals on oil changes and these bearing issues? Based on my experience in industry, I see more issues with contamination than degradation of the oil. I would think that M1 or TWS that both will look pretty good after 5k miles and even after 10k miles.

I'm pretty sure most M3s are driven less than 10k miles per year. So maybe contaminated oil is contributing to accelerated bearing wear in some cases.