[Pladi]

Originally Posted by Jeyoller

Not sure whether or not they'd be tearing it apart completely since it'll be a warranty claim but it actually just sounded like belt tensioner / pulleys when i took it in (plus some suspension issues which was my main concern for the warranty claim) and it turned out to be coming from inside the engine.... so im patiently waiting to hear back from them now

Rod knock is pretty distinct esp at idle and it comes from down low.

But knocking noises inside the engine can be sooo difficult to pinpoint.

[SnapCoupe]

Originally Posted by Pladi

Rod knock is pretty distinct esp at idle and it comes from down low.

But knocking noises inside the engine can be sooo difficult to pinpoint.

When my bearings went the knock was only noticeable between 2000-2400 RPM. Idle and everywhere else in the rev range sounded normal. The car even drove fine (though I never tried to push it as I was limping it in to my dealer). When I finally noticed the knock it was when I was parking with the window down.

[Pladi]

Originally Posted by SnapCoupe

When my bearings went the knock was only noticeable between 2000-2400 RPM. Idle and everywhere else in the rev range sounded normal. The car even drove fine (though I never tried to push it as I was limping it in to my dealer). When I finally noticed the knock it was when I was parking with the window down.

yes makes sense. They do come in different sizes and flavors thats for sure.

[Welcome to NBA Jam]

Originally Posted by SnapCoupe

When my bearings went the knock was only noticeable between 2000-2400 RPM. Idle and everywhere else in the rev range sounded normal. The car even drove fine (though I never tried to push it as I was limping it in to my dealer). When I finally noticed the knock it was when I was parking with the window down.

This seems to be the most typical of the symptoms for those with rod knock. 2-2.5k rpms will make a distinct clacking noise that can be described only as "Well that doesn't sound good."

[SnapCoupe]

Originally Posted by Welcome to NBA Jam

This seems to be the most typical of the symptoms for those with rod knock. 2-2.5k rpms will make a distinct clacking noise that can be described only as "Well that doesn't sound good."

Yup.

I just wish I knew what I do know about not driving the car after it initially seized. When it happened I guess I was in denial that it could've been anything major, so when I was able to start the car back up an hour or so after it cooled down, I figured if it drove fine I wouldn't have to call a tow.

Knowing what I know now, if I just towed it from where it seized I probably could've replaced the bearings and been fine. After driving on it, not so much.

[MTK24]

oil analysis after switching to from liqui moly 5w40 to liqui moly 5w30. Car has a lower idle and runs smoother.

There is really no reason for running 5w40 on these engines. The whole thick oil keeping the engine cooler is insignificant. And I drive the car hard/do a lot of highway pulls.

[Welcome to NBA Jam]

5w40 significantly decreased my oil consumption. I went from a quart every 6,000 miles to none.

[Kevin39]

Do people with tuned cars actually go 6,000 miles between oil changes anyway?

[Welcome to NBA Jam]

Originally Posted by Kevin39

Do people with tuned cars actually go 6,000 miles between oil changes anyway?

Yes, I go 12-15k, or one year.

[Bours]

im back on track with a built engine ! i had a rod bearing failure at 150 000 kms !

[Pladi]

Originally Posted by Bours

im back on track with a built engine ! i had a rod bearing failure at 150 000 kms !

Good to hear man, who did you end up going with the build ? Ill PM you wanted to hear on some details.

[Pladi]

Originally Posted by Bours

im back on track with a built engine ! i had a rod bearing failure at 150 000 kms !

Just so everyone knows though you were HEAVY modded running 100 % meth i want to make that clear LOL.

[Herakles]

Originally Posted by Jeyoller

Hey everyone!

Opening this thread to see how reliable has been the n55 engine to everyone here in the forum. I've recently moved from an n54 platform to an N55 (feel like it was a mistake) for "reliability" purposes but now that i got mine i did a little bit more research and i've been finding a lot of people with engine rod bearings going bad on them. My car currently have 75k and have had these parts replaced (under warranty)


2011 N55 E90 75k


Valve cover
Valve cover gasket
OFHG (oil filter housing gasket) - I've read this is a common thing that if done wrong could get gasket pigments into the engine and damage the rod bearings

Mods:
Stock


If you guys can post your year, millage, mods and problems you've encountered with your n55 platform that'd be awesome for research/documentation purposes.

Here the links i've found so far:

Forums
http://www.e90post.com/forums/showth...ht=rod+bearing

http://www.e90post.com/forums/showthread.php?t=883580


Youtube:

@335MRod

Thanks in advance to anyone that helps with the information gathering! BTW has anyone make it to 125k in an N55 platform???

I have a 2011 335 xdrive- I saw the rod bearing video on YouTube and actually came here to see if anyone has been unfortunate to see this issue?

Mine has 42k miles, been on mhd s1 for a few months now but thinking about going back to stock just to take it easy on the engine.

I always had the ticking noise - thought that was normal

Under warranty (now outside of warranty)
-water pump failure at 20k miles
-oil filter gasket

Reading all this makes me want to sell my car! It would be horrible to need a motor replacement

[Welcome to NBA Jam]

Don't let one video freak you out. Well over 99% of all N55s ever sold do not have rod bearing problems. This is an isolated issue with no known cause. You're looking at a subset of people who were unfortunate enough to experience this problem, and have gathered in one place to discuss it. Even if a full 1% of N55s had a problem this severe, we'd have heard about it by now.

An analogy would be like going to a cancer support group, listening to their symptoms that they had before they got cancer, and assuming that you have cancer because you have a small cough.

It's good to recognize what the problem sounds like and be aware that it exists, but don't sell your car over it.

[9krpmrx8]

Exactly, this is my post from another thread.

BMW doesn't release model specific sales data but millions of E9X, E8X, E7X, E60, X6, F01, Z4, F2X, F06, F10, F11, F12, F15, F16, and many more, were sold. So the number of models that were equipped with the N54 and N55 is a shit ton so a couple of forum posts about failures that may or may not be related to design flaw in the engine doesn't mean shit. Especially when you consider most of the N55 failures I have seen on this forum have not been on stock cars, but fairly modified and tuned ones and on most the failure mode is mostly a guess as very few have had the engines torn apart and shared the results.

Now think of all the models that were equipped with the N54 or N55 in this time period and look at these numbers.

[tomo7772]

Sorry, My ride is not E90, it's F32 435i, but same N55

My N55 had...

Dinan big turbo

Wagner evo2

charge pipe

S55 oil pan

ER big oil cooler

After several Gymkhana (something like autocross) run, it was gone.
It might be cause of rod bearing issue or low oil pressure, could be both.

I changed the oil every 3000km(1875mile), And the oil was MOTUL 300V 5W-40 which is race proven. Even NISMO use the oil for races.

Actually, this is the second time of seized N55. I mean I had blown N55 TWO TIMES a year! First time, I thought it was caused of oil pan because stock N55 does not have baffle, so the motor bit some air, and got damage for the rod bearing. That's what I was thinking. Then, I changed M4's oil pan, and installed ER oil cooler, but did not work.

My first N55 was run only 13750 miles and gone. Second one which I bought from junk yard was run around 34000 miles. And after 3000 miles of track and autocross, it's gone. I really don't know what I need to do for next engine... I might be better swap to S55?

First N55

Second N55

S55 oil pan

[bbnks2]

Originally Posted by tomo7772

Sorry, My ride is not E90, it's F32 435i, but same N55

My N55 had...

Dinan big turbo

Wagner evo2

charge pipe

S55 oil pan

ER big oil cooler

After several Gymkhana (something like autocross) run, it was gone.
It might be cause of rod bearing issue or low oil pressure, could be both.

I changed the oil every 3000km(1875mile), And the oil was MOTUL 300V 5W-40 which is race proven. Even NISMO use the oil for races.

Actually, this is the second time of seized N55. I mean I had blown N55 TWO TIMES a year! First time, I thought it was caused of oil pan because stock N55 does not have baffle, so the motor bit some air, and got damage for the rod bearing. That's what I was thinking. Then, I changed M4's oil pan, and installed ER oil cooler, but did not work.

My first N55 was run only 13750 miles and gone. Second one which I bought from junk yard was run around 34000 miles. And after 3000 miles of track and autocross, it's gone. I really don't know what I need to do for next engine... I might be better swap to S55?

First N55
Attachment 1944024
Second N55
Attachment 1944027
S55 oil pan
Attachment 1944026

That is two pretty catastrophic failures to be rod bearing failure... Did you over-rev these engines? Spent a lot of time banging off the rev limiter? The big end of the rod is pretty blackened, but, that rod looks like it bent and snapped. I had 3 spun bearings on my engine and the rods did not bend or break lol...

What kind of tuning was on these cars? Any logs?

[9krpmrx8]

Yeah my guess is these failures are due to abuse. It's a 435i, not a 1991 240sx.

[Pladi]

Originally Posted by bbnks2

That is two pretty catastrophic failures to be rod bearing failure... Did you over-rev these engines? Spent a lot of time banging off the rev limiter? The big end of the rod is pretty blackened, but, that rod looks like it bent and snapped. I had 3 spun bearings on my engine and the rods did not bend or break lol...

What kind of tuning was on these cars? Any logs?

Those failures are 100 percent fueling issues and detonation.

This thread is about rod failures with cars that are not tracked.

[tomo7772]

435i has smart 8AT with paddle. This is not DCT or DSG. It means we can not over-rev and banging during running. Of cource, if you shift to the N position, you can do that, but there is no meaning.

After the catastrophy, we had checked the car with logger, And there were no detonation or misfire codes. That's why I am struggling. If I can determine the source of trouble or blow, I can deal with it. However, If I can not figure out, I might will be blow third engine.

There are sooo many RB, JZ or SR specialist in my country, but they are not familiar with N54, N55, S55. I just wanna gather all kinds of info about N55 troubles for next step.

[TheMidnightNarwhal]

Originally Posted by tomo7772

435i has smart 8AT with paddle. This is not DCT or DSG. It means we can not over-rev and banging during running. Of cource, if you shift to the N position, you can do that, but there is no meaning.

After the catastrophy, we had checked the car with logger, And there were no detonation or misfire codes. That's why I am struggling. If I can determine the source of trouble or blow, I can deal with it. However, If I can not figure out, I might will be blow third engine.

There are sooo many RB, JZ or SR specialist in my country, but they are not familiar with N54, N55, S55. I just wanna gather all kinds of info about N55 troubles for next step.

Dayum dude, you have unlimitted funding or what

Nice car by the way, I looked at your thread!

[bbnks2]

Originally Posted by Vampire335i

The whole thick oil keeping the engine cooler is insignificant. And I drive the car hard/do a lot of highway pulls.

Thick oil does not keep oil cooler. Not sure why so many people keep posting that here... Thicker oil will always produce more heat.

People just don't understand that not all 40weight oils are the same. Some are thinner or thicker on the "weight" scale. Some 0-40wt oils can be THINNER at operating temperature, or on a cold start, than a 0-30. Oils viscosity flexes with temperature and no 1 oil has the same temperature curve... formulation of the "base stock" can significantly impact an oils viscosity index.