[Bmwfixerguy]

So I will start by saying I have been turning wrenches for BMW for over 12 years... Well before this engine was even out in the US market... I have NEVER SEEN A CRACKED CYL LINER EVER!

-The story- buddy who works next to me has a 335xi, exhaust, dps, jb4, meth and dci.
He's been complaining of a detonation type noise.. We log and log and all looks well with no signs of detonation.. The noise comes and goes.. Fast forward a week or two and were getting closer and closer to the noise, 30 techs in the shop and no one has ever heard this noise.
Finally one day we are leaving work and he screams for me it's loud it's loud! I jump into his engine bay and start reaching for it I can hear it really loud! Finally we find the noise. Back of the head gasket is blown out leaking compression out the back! Haha it was an exhaust leak esentially and that's what it sounded like..
Three days later plan is set.. Drop motor, trans and subframe and make it easy.. I didn't stay last night but they had it all dropped on the engine table in 50 minutes..
This am he starts yanking the head. Head off and great let's gasket her and back together and start by lunch time..
We notice wizzy wheel/high speed die grinder cookie marks all over the the heads mating surface... FUCKKKK THIS HEAD HAS BEEN OFF BEFORE! Why why was this head off.. N54 heads don't ever come off who took a wizzy wheel to this thing like a savage??
We look deeper.. As you can see in the pics we find some ugly ugly stuff...
Cracked liner in cylinder 3..

-cause- the cause is unknown at the moment but I'm gonna straight edge the head and deck Monday morning. I feel like the liner was able to shift up from lack of head pressure and material being removed from the head and I wanna confirm my theory with a straight edge and light... I'm open to all ideas that's why I'm posting from curiosity I guess...

-symptoms- there was zero symptoms from the CRACKED LINER.. The LINER was well cracked before the gasket failed.. No noise from cyl 3 area. No symptom signs on the plug not nothing and the car pull good And all logs looked good too

[B@man335]

Jeez bro

[Bmwfixerguy]

It's very very hard to see in the pictures but the cylinder liner is raised over the deck probably a good few hundreths not thousands .. Enough that any old lamen could feel it and know it's very wrong lol..
It can only come up one way.. Of it has room just like a wisdom tooth

[Dmak]

This is pretty crazy. I seen rod out the block on bmw but I never seen anything like this either. Worked at bmw for 7.5yr. Replaced n54 head gasket under warranty b4 due to leaking.

I almost think the liner moved after it cracked. Maybe since there's a crack when heat up and cool down causing the liner to slowly move on its own. (liner is not as tight anymore due to the crack)
Seeing how it discolor there, looks like lot of heat is at that spot(which might also be after the crack is already form, I don't know)
Next will need to pull the piston and check on the rings.

If the cause is due to not enough or uneven pressure from the head. I would think the engine would have head gasket leak(combustion into coolant) b4 the liner has time to move like that.

I think what's important now is can the liner be replace and save the block.

Ps. Maybe send the pictures to puma and see if they seen it b4.

[Bmwfixerguy]

Originally Posted by Dmak

This is pretty crazy. I seen rod out the block on bmw but I never seen anything like this either. Worked at bmw for 7.5yr. Replaced n54 head gasket under warranty b4 due to leaking.

I almost think the liner moved after it cracked. Maybe since there's a crack when heat up and cool down causing the liner to slowly move on its own. (liner is not as tight anymore due to the crack)
Seeing how it discolor there, looks like lot of heat is at that spot(which might also be after the crack is already form, I don't know)
Next will need to pull the piston and check on the rings.

If the cause is due to not enough or uneven pressure from the head. I would think the engine would have head gasket leak(combustion into coolant) b4 the liner has time to move like that.

I think what's important now is can the liner be replace and save the block.

Ps. Maybe send the pictures to puma and see if they seen it b4.

All those things are very possible and I'm the and no one will really know.. The car has 160 in it so will never get a single thing done with PUMA lol They will say thanks for the pics under investigation thanks bye felica lol.
That was my other thought as well that the crack happened then it moves because it gave it a tad more room.
The bottom line is the head was off and someone did there own gas station head resurfacing, the car was bought at a used lot awhile ago because it was the only xi 6spd in black he could find in the East coast at the time..

Side note I have never seen one done (head gasket) that I can rwmwber. Maybe 1 or 2 misdiagnosed early in as head gaskets that were actually oil filter housing gasket leaks or what not..
The gasket was all deformed in the back allowing compression out the back of the head/block.
When you work on the cars everyday you just know when you have something that isn't normal and diant usually fail and it prompts you to dig deeper ya know.. Like an intuition!
This was one of them and it's got bad news all over it.

In the good side we have a long block on deck for it ready to go in

[jtswole]

Only time I see blown motors are cars that run meth lol.

[Bmwfixerguy]

Originally Posted by jtswole

Only time I see blown motors are cars that run meth lol.

Do tell? I personally think meth when used properly is just another "fuel" that allows for a bit of timing and boost

This engine didn't stand a chance from the beginning... This wasn't meth..

[135Pats]

Interesting failure for sure. The cross hatching is still in really good shape but clearly there's some type of hot spot around the crack.

OP, what octane (ballpark) was the car tuned for? I'd say long-term detonation but the piston still looks to be in good shape. How do the rings look in that cylinder?

[ferocity02]

Originally Posted by jtswole

Only time I see blown motors are cars that run meth lol.

This is not a meth-related issue. Cylinders are pretty strong and relatively "low-stress". There are many other parts that will fail first. The only time I've seen a damaged cylinder is when something else lets go first.

This looks like a manufacturing defect that grew worse over time, or was caused by a botched repair job as evidenced by the mating surface markings that the OP noticed.

[Jeff@TopGearSolutions]

Originally Posted by Bmwfixerguy

Do tell? I personally think meth when used properly is just another "fuel" that allows for a bit of timing and boost

This engine didn't stand a chance from the beginning... This wasn't meth..

Meth with proper flow and distribution is fine.

The problem the N54 market is slowly seeing is running max boost and ignition on the brink of detonation and not having = flow to all cylinders

[jtswole]

Originally Posted by Bmwfixerguy

Do tell? I personally think meth when used properly is just another "fuel" that allows for a bit of timing and boost

This engine didn't stand a chance from the beginning... This wasn't meth..

Maybe not this motor, specifically, but in general people use it as a means to raise fuel volume, instead of using proper fuel solution. That is a unique looks crack though.

[Jeff@TopGearSolutions]

I can only speculate that the car previously over-heated (likely due to running with no coolant). As we know the N54 loves to eat coolant or water pump failure.

Head gasket failure, possibly intrusion of water on the hot sleeve fractured the metal.

Detonation or just cylinder pressure cracked the sleeve further down the road. (assuming no knock).

Something like that.

[Bmwfixerguy]

Originally Posted by Jeff@TopGearSolutions

Meth with proper flow and distribution is fine.

The problem the N54 market is slowly seeing is running max boost and ignition on the brink of detonation and not having = flow to all cylinders

Agreed... I know everyone has there own thoughts of how and what is right and wrong.. I think. Multiple smaller nozzles is better than fewer bigger nozzles. I like way more meth than water (like 100% meth lol)
I like nozzles close to the throttle and a good intercooler to help out a bunch..
How much of that is wrong? Probably most of it lol but it makes sense in my head lol

I also have only run ots meth maps (map 3) and have never ran a custom map, although I want one

[WedgePerformance]

Originally Posted by Jeff@TopGearSolutions

I can only speculate that the car previously over-heated (likely due to running with no coolant). As we know the N54 loves to eat coolant or water pump failure.

Head gasket failure, possibly intrusion of water on the hot sleeve fractured the metal.

Detonation or just cylinder pressure cracked the sleeve further down the road. (assuming no knock).

Something like that.

It's almost impossible to overhead this car. As soon as the pump fails hits a specified temp the kombi goes yellow and less then 1 min later it turns red and shuts the car down. It happens that quick.

[V8bait]

Only thing i can think of that could cause that kind of crack would be heating/cooling cycles. I doubt knock did it or anything like that, but different expansion between the liner and the block coupled with a weak point could cause a crack that could expand over time like that. A hot tune could compound it (high boost low timing, high cylinder pressures with high heat transfers to the sleeve etc).

[Bmwfixerguy]

Originally Posted by Jeff@TopGearSolutions

I can only speculate that the car previously over-heated (likely due to running with no coolant). As we know the N54 loves to eat coolant or water pump failure.

Head gasket failure, possibly intrusion of water on the hot sleeve fractured the metal.

Detonation or just cylinder pressure cracked the sleeve further down the road. (assuming no knock).

Something like that.

Ok So here's something to take note of for the future... When I had my pump out Doing inlets the other week I noticed plastic pieces in the impeller of the water pump... They are old pices of a previously failed water pump..
In the engine you see above there were tons of these pieces all around the coolant jacket side of the cracked liner...probably just coincidence but they could be blockage points of gpu fleas other areas

[V8bait]

Originally Posted by Bmwfixerguy

Ok So here's something to take note of for the future... When I had my pump out Doing inlets the other week I noticed plastic pieces in the impeller of the water pump... They are old pices of a previously failed water pump..
In the engine you see above there were tons of these pieces all around the coolant jacket side of the cracked liner...probably just coincidence but they could be blockage points of gpu fleas other areas

You should check your expansion tank and coolant level sensor very thoroughly and report back if you notice any brittle/broken bits.

[Bmwfixerguy]

Originally Posted by WedgePerformance

It's almost impossible to overhead this car. As soon as the pump fails hits a specified temp the kombi goes yellow and less then 1 min later it turns red and shuts the car down. It happens that quick.

Hello Mr wedge lol... Not to highjack my own thread lol.. But I just recently stacked your product with my jb4..
335I 6spd
Fbo meth, intercooler, and mmp inlets and outlets... In running the race flash..

Would I be able to send logs to this user name once the weather clears up? As soon as I load in the bef the car just looses its balls.. Yes I'm making boost and moving along but it's sooooo unagressive... Kinda like a sick Mike Tyson.. Its still pretty mean just not the same snap it use to have lol
Is it common to need to make custom alterations? Is the inlets and outlets not suited for the race bef? The log will tell it all hopefully tomorrow

[feuer]

Originally Posted by Bmwfixerguy

This engine didn't stand a chance from the beginning... This wasn't meth..

Well, you already know that it was open prior and the knocks were there. Is possible that partial overhaul wasn't done correctly and the liner was damaged during install. I'm surprised that it didn't cause any issues earlier as the crack seems to have been there for a while and engine was tune. Like making to much pressure into the coolant which won't be able to circulate thus overheating the engine or mixing oil and coolant.

[Miller335]

Originally Posted by feuer

Well, you already know that it was open prior and the knocks were there. Is possible that partial overhaul wasn't done correctly and the liner was damaged during install. I'm surprised that it didn't cause any issues earlier as the crack seems to have been there for a while and engine was tune. Like making to much pressure into the coolant which won't be able to circulate thus overheating the engine or mixing oil and coolant.

Pretty much all bets are off at that point.
For all we know this engine lasted longer than it should have.

Good thread nonetheless.

[Bmwfixerguy]

Originally Posted by Miller335

Pretty much all bets are off at that point.
For all we know this engine lasted longer than it should have.

Good thread nonetheless.

It definitely lasted longer that it was supposed too! Cyl 3 issue wasn't even why it was coming apart! And we only searched for more issues after the we saw the butchering of the heads mating surfface

[Jeff@TopGearSolutions]

Originally Posted by WedgePerformance

It's almost impossible to overhead this car. As soon as the pump fails hits a specified temp the kombi goes yellow and less then 1 min later it turns red and shuts the car down. It happens that quick.

Keyword almost impossible. Then again, this issue here is part of that almost impossible.

The head was already off? So why else would the head be off if not for a blown gasket. Only other scenario where the head gasket blows besides over heating is too much boost? This car isn't notorious for blowing head gaskets otherwise.

If you have a better theory I'm all ears, I was just speaking out loud and throwing ideas out