[xxMike61]

I've been thinking of compiling every N55 engine failure I can find into one large data sheet. As our cars gain miles (and on top of being tuned) I think it's important to see what could potentially lie ahead with the worst case being a destroyed engine.

Now I love my car to death and I don't really have a big enough wallet to deal with something like that if it were to happen. Having somewhat of a scientific background, I really want to do everything I can to try to get to the bottom of why stock cars and heavily tuned cars (some with every maintenance under the sun done to them) alike seem to almost spontaneously destroy themselves.

So I'm really willing to put in the effort to see if there is any real root cause of this issue and was just wondering if anyone else was?

__________________________________________________ ________________________
This is what I have so far from only searching on e90post:

https://docs.google.com/spreadsheets...it?usp=sharing

[Mean E92]

Wow we all seem to be 2011.

[bbnks2]

Maybe check to see where they were all built?

This list is not going to get you very far.

[Turbod]

Bours was the mechanics fault for not installing the oil pump correctly.

[9krpmrx8]

Yeah I know the internet seems to think it's a problem, but it's really not. A local member and long time dealer tech has only seen it happen a few times since the N55 was released and most were on cars that were not really being maintained well, only one that he could recall was in a low mileage X3 that was maintained by the dealer. And he said he can think of just as many engine failures on just about every BMW engine since it just happens.

[Pladi]

@Bours He was running 100% meth i believe with melted spark plugs.

Hey bours any update buddy on your new build ?

But yes its interesting that they are all 2011. What we need from the owners is the build date of the car. Month/Year.

[orteeze]

Thought about reaching out to these guys and inquiring about what type of oil they use?

[bbnks2]

Originally Posted by orteeze

Thought about reaching out to these guys and inquiring about what type of oil they use?

Not likely oil has anything to do whit it. Oil pressure? YES. Loss of oil flow? YES. Oil itself? Nope.

The only thing I find this list useful for is showing the 2011 trend which might point to a specific production run or country of manufacturing... Should run the last 7 of the vins and see where they were built and when.

BMW put these rod bearings in almost all their motors... I have read though that some motors got 1 or 2 different bearings for whatever reason... when torn down you're supposed to check what color your car had and replace with the same even though they are all supposed to be 50mm. No one tore down their motor though so good luck finding a trend there.

[lwgrenier]

Also what might be helpful is seeing how many users have seen this post compared to how many have had the issue. Might be good to start another sheet where people can comment if they had not had the issue so over time you can come up with a percentage w/ confidence intervals.

[SnapCoupe]

I was victim to rod bearing failure at 84k miles. Car was all stock and very well maintained up until 70k miles when I purchased it. From there, the oil was changed with BMW 5W-30 at roughly 6k mile increments. All other maintenance and issues were taken care of by me after I took ownership as well. At around 78k miles I started modifying the car with Stage 2 bolt ons. Car was running great with no codes up until the motor seized under throttle in second gear. Copper flakes all in the oil suggested the rod bearings had failed.

[maddmatth]

I think there was a production fault with engines built around April 2010. One of the head bolts was not fully tightened at the factory.

I've seen a few cases of head-gasket like failure symptoms online, that turned out to be a loose head bolt by cylinder 6.
My car had a coolant loss that I couldn't solve for years, sometimes it would spray out the cap. Would trigger the coolant light about 2000km after topping up and seemed to be getting worse over time.
It was finally solved when the workshop opened the engine and found the loose head bolt.

I've seen some other with more severe symptoms, another guy had coolant shoot out when he accelerate hard, where the same head bolt was loose. Their cars were built around the same time from what I recall.

Last 7 VIN digits are E397157, April 2010 build.
In the US you might consider this a 2011 model? Here in NZ it's registered as a 2010.

Maybe in cases where the coolant loss isn't as obvious, this could lead to gradual oil contamination which goes unnoticed and wears down the rod bearings??

[Turbod]

Originally Posted by Pladi

@Bours He was running 100% meth i believe with melted spark plugs.

Hey bours any update buddy on your new build ?

But yes its interesting that they are all 2011. What we need from the owners is the build date of the car. Month/Year.

Bours is on vacation and I don't think he is getting on the internet while he is gone. I never actually saw a photo of the cylinder 1 spark plug. I know the timing jumped and when it was "fixed" the mechanic messed up the oil pump install which is what caused the bearing to spin.

[Pladi]

Originally Posted by SnapCoupe

I was victim to rod bearing failure at 84k miles. Car was all stock and very well maintained up until 70k miles when I purchased it. From there, the oil was changed with BMW 5W-30 at roughly 6k mile increments. All other maintenance and issues were taken care of by me after I took ownership as well. At around 78k miles I started modifying the car with Stage 2 bolt ons. Car was running great with no codes up until the motor seized under throttle in second gear. Copper flakes all in the oil suggested the rod bearings had failed.

Still we dont get the most important information... BUILD DATE Country of engine build.

[SnapCoupe]

Originally Posted by Pladi

Still we dont get the most important information... BUILD DATE Country of engine build.

My bad, forgot to paste the info I pulled off my VIN on my original post.

The build date is October, 2010. I pulled my VIN up on BMW's system but I an unable to find the origination of the engine. Would it be the same as the original build location for the car?

[Dsinewave]

Hey I’d like to add my car to this list. (Sadly as I love my car too)

201 335i, FBO, perfectly maintained with oil changes @5,000Ks, siezed without warning a few weeks ago. 60,000Kms on mine.

January 2011 build

[Pladi]

Originally Posted by SnapCoupe

My bad, forgot to paste the info I pulled off my VIN on my original post.

The build date is October, 2010. I pulled my VIN up on BMW's system but I an unable to find the origination of the engine. Would it be the same as the original build location for the car?

Thanks snap, i honestly dont know if engine assembly is the same as car. I believe not but someone else can maybe confirm that.

But the build date also very important so far we have a jan/11 and october/2010. Was car assembled in Munich ?

[ignote]

Wouldn't this an imminent failure likely show up in the wear metals of a used oil analysis?

[9krpmrx8]

Yes it would. These failures are extremely rare and almost always on modified cars and not with the original owner, lot's of variables.

I am at 95k, FBO, stage 2+. I oil test twice a year or so and so far wear metal levels are great.

[Pladi]

I did an oil analysis recently and it was all excellent but i wonder how much we can trust the black stone report. As far as i am concerned they can punch any value there we dont know for sure they are using real data all the time.. (i know probably very unreasonable of me) but does that make any sense .. ? It would obv be impossible for us to confirm that its real data lol.

[Veilside]

Hello all,

I would like to add some useful information into this thread since I also own a 2011 N55 335i with currently about 86 000 miles. My production date was 02/10 Munich, Germany. All stock. So far I have done two Blackstone Oil analysis.

The first oil analysis was done at 81 000 miles and came out pretty bad as the iron level was a little too high. It may be the cause long oil interval at around 7500 miles with the original 5w-30 BMW Oil, and also it was during winter times hence maybe the freezing cold start may have cause some harm here in Canada.

The second one was done at about 86 000 miles however was very good as all the metals were lower than average and the oil was changed at about 5000 miles. I was also using Liqui-moly 5w-40 during that time.

Maintenance done so far were:
- OFHG @ 81 000 miles
- Serpentine belt @ 81 000 miles
- Coolant expansion tank @ 81 000 miles
- Spark plugs @ 60 000 miles
- water pump @ 65 000 miles

Recall for VANOS bolt were done in 2014, and I am currently the 2nd owner. Car were always warmed up with the oil temp to 2 notches on the gauge before beating on it. Have been using 91 shell ever since I owned the car.

[9krpmrx8]

Originally Posted by Pladi

I did an oil analysis recently and it was all excellent but i wonder how much we can trust the black stone report. As far as i am concerned they can punch any value there we dont know for sure they are using real data all the time.. (i know probably very unreasonable of me) but does that make any sense .. ? It would obv be impossible for us to confirm that its real data lol.

I have been using them for years and they saved me a lot of money on my turbo RX-8 when they found very slight traces of coolant in the oil. This allowed me to pull the engine and rebuild it before I ruined some expensive hard parts.

Another time, I sent a sample from a known low compression engine just to see what they would say. I did not mention any problems with the engine and when I got the test results back, it basically said that the engine was going to blow.

I also ran a OIC of Castrol Edge for one cycle and did not notify them and the test report came back warning me of the titanium in the oil because they thought I was using my normal M1 0W-40 and it does not contain titanium but Castrol Edge 0W-40 does.

So I trust the reports. Lot's of M3 guys use them and plenty have been warned of excessive bearing wear. But there are other companies as well.

[fatty335]

All - I have been reading up on this recently and some report similar failures immediately following an OFHG replacement. I suppose not draining the coolant and allowing it to dump into the crankcase could introduce enough coolant into the oil to cause an issue? Perhaps it is worth tracking how many of these happened around the same time as an OFHG replacement...just a thought. Other things that could be causal that are circulating around the forums:
- an overheating event (likely WP failure)
- tight factory bearing clearance exacerbated by increased power demand (tune)
- production/manufacturing change/part update
- long factory oil drain intervals