[stratos_335]

Hi E90post community,

yet another thread of an engine blown.

It lasted for 60.000 km. Tunes: FBO + meth + Rev. 3 agressive maps + RB turbos.

It started after changing the oil which is a coincidence. The BOV started squirting oil vapors and after a short ride the left exhaust (individual exhaust pipes for each turbo - bank) started smoking blueish smoke.

The very next day I took the car for a short ride. The exhaust was starting smoking much more, SES and limp mode, I returned home with 1 cyl misfiring.

Compression test to all of the cylinders, 11:1 for all the cylinders, 0.1 for cylinder 2.

Engine dissembled and here it is.

Probably bad injector, stopped injecting fuel, temperature was risen and it finally melted.

All of these because of a bad injector. I will not rebuild the engine as the sleeve is damaged, will buy a used engine.

Discussion please

[RimasRS]

could it be blown turbo in the first place and then it went further

[Tiago@VRSF]

How do the other pistons look? Did it throw any codes? Did you have canclear on? Any pics of the injector?

[135Pats]

The sleeve damage makes me sad, was hoping you could "just" swap out the nuked piston. Man that crown and ring are just totally blown to pieces…Have you checked out the injector for that cylinder? I don't think I've come across this issue before, then again we don't see many outright blown N54s. This is pure 100% speculation on my part, but things could have gotten too hot due to a lack of meth and/or fuel in cylinder. Good luck finding a new motor, sorry for the loss man.

[lol slow]

it sucks how such small parts that can fail quite easily effect the motor in such a drastic way. Isn't there a way to monitor this, like would an AFR gauge be able to save you and know that the injector wasting opening?

[deathbunny]

The DME monitors so many things to prevent failure. You would think that if a failed injector could cause so much damage they would have came up with a way to monitor them in case of failure.

Sorry for your loss

[Tiago@VRSF]

Originally Posted by deathbunny

The DME monitors so many things to prevent failure. You would think that if a failed injector could cause so much damage they would have came up with a way to monitor them in case of failure.

Sorry for your loss

They DME can and will detect a failed/failing injector, which is why I'm curious if canclear was on or if any codes were thrown. I can't imagine a car with a melted/cracked piston wouldn't throw a code or two.

[135Pats]

Perhaps sudden loss of meth flow, or sudden loss of sufficient flow to that particular cylinder is probably more accurate….Though Cyl 2 usually gets sprayed pretty well, it isn't the one that tends to get meth starved on CP located setups. If an injector suddenly gave up the ghost, the DME would shut that cylinder down ASAP. Like others have said, it's hard to believe such a catasrophic failure only resulted in a misfire. Would think you'd have tons of codes, and the car would be completely undriveable.

[SflBimmer8484]

We have seen a couple n54's with leaking injectors with 0 codes thrown.

[CHECKERED]

Originally Posted by Tiago@VRSF

They DME can and will detect a failed/failing injector, which is why I'm curious if canclear was on or if any codes were thrown. I can't imagine a car with a melted/cracked piston wouldn't throw a code or two.

I was under a similar impression, there is no way a cylinder(injector) stopped working and the DME didn’t throw lean condition in bank 1 code, unless the tune/piggyback was on auto clear…doesn’t make sense

[stratos_335]

Sorry for my bad English, I'm so frustrated that even my comprehension has gone bad.

Originally Posted by RimasRS

could it be blown turbo in the first place and then it went further

No, both turbos are fine, I checked them myself a few hours ago.

Originally Posted by Tiago@VRSF

How do the other pistons look? Did it throw any codes? Did you have canclear on? Any pics of the injector?

Sorry, no pics from the injector and not tested yet. But I'll have some pics and bench test soon.

Originally Posted by 135Pats

The sleeve damage makes me sad, was hoping you could "just" swap out the nuked piston. Man that crown and ring are just totally blown to pieces…Have you checked out the injector for that cylinder? I don't think I've come across this issue before, then again we don't see many outright blown N54s. This is pure 100% speculation on my part, but things could have gotten too hot due to a lack of meth and/or fuel in cylinder. Good luck finding a new motor, sorry for the loss man.

Thanks mate. The damage on the sleeve is the worst part.

Just for info, there are cast iron (and maybe coated) sleeves for all cylinders. Machining the sleeve and ordering custom pistons is a solution but the cost probably will exceed a used motor to have my car back to the road.

One option is to remove the sleeve, order a new one from Darton or another company, put the sleeve back, machine and hone it, put new OEM pistons (yes they are forged) and re-assemble the engine.

That will lead to an engine that can be easily damaged in the future. In this scenario I forget boost over 15 psi and meth and I'll be driving a car prominent to damage.

A low mileage used engine will be a more secure option

Originally Posted by lol slow

it sucks how such small parts that can fail quite easily effect the motor in such a drastic way. Isn't there a way to monitor this, like would an AFR gauge be able to save you and know that the injector wasting opening?

I have the in-dash AFR monitor that Procede provides. It is not easy looking at it when accelerating. This might have caused by a short lean burn condition that is difficult to be monitored.

This happened when I was cruising around, not when pushing the car hard.

Originally Posted by deathbunny

The DME monitors so many things to prevent failure. You would think that if a failed injector could cause so much damage they would have came up with a way to monitor them in case of failure.

Sorry for your loss

I had can-clear off all the time as p3cars gauge monitors all fault codes. No codes regarding lean combustion poped up when driving

Originally Posted by Tiago@VRSF

They DME can and will detect a failed/failing injector, which is why I'm curious if canclear was on or if any codes were thrown. I can't imagine a car with a melted/cracked piston wouldn't throw a code or two.

Look above. No codes regarding combustion and injectors

Originally Posted by Andrew@ActiveAutowerke

We have seen a couple n54's with leaking injectors with 0 codes thrown.

[stratos_335]

Originally Posted by CHECKERED

I was under a similar impression, there is no way a cylinder stopped working and the DME didn’t throw lean condition in bank 1 code, unless the tune/piggyback was on auto clear…doesn’t make sense

Can-clear was off all the time. This is weird

[Chris_506]

man shit like this makes you question whether it is worth paying 50k for a car that comes with problems that can cause this, their(bmw) shitty injectors and fuel pumps on n54 engines are something they should be responsible for thru ought the life of the engine because it was a defect from the manufacturer

[Continue5]

Sorry to hear OP, at this point it does make much more sense to just grab a used n54 and call it a day. If you are doing the replacement yourself it shouldn't be too painful. Also pistons are not forged as once thought but cast hypereutectic. Here is an engine that might work : http://www.ebay.com/itm/BMW-E71-X6-X...01bfd6&vxp=mtr.
Good luck with everything

[-Wingman-]

The pistons are forged, how could this have happened?!

[Rob@RBTurbo]

Originally Posted by stratos_335

No, both turbos are fine, I checked them myself a few hours ago.

Sorry about your misfortune stratos. As I said via email feel free to send the RBs back in if you'd like them rebuilt for good measure (highly recommended). Especially now that you have some time available to get it done while your working on the engine remedy.

Originally Posted by stratos_335

put new OEM pistons (yes they are forged) and re-assemble the engine.

Please take a pic of the underside of the piston. No forged piston has ever been documented for the N54 so it would be interesting to see this portion. Based on the pics provided it appears to be just like the other cast N54 pistons I have seen. Based on the failure also leads me to believe it is cast. Nothing wrong with Cast pistons, in fact they have proven to be able to withstand quite the load- just want to clear up the "yes they are forged" before it spreads like wild fire.

Rob

[onesuperboi]

Are you sure the failure is caused by a faulty injector?

There was another thread with a engine fire and that have been caused by a faulty injector. I can't imagine why a faulty injector would cause a fire in one situation, and an internal failure in another.

[Mike@N54Tuning.com]

Sucks it broke but at those power levels it's somewhat inevitable. I wonder if a single turbo setup would actually be more reliable than RB turbos despite making 100-200hp more due to the reduced exhaust back pressure?

On the damage it looks like typical N54 knock damage to me. Perhaps it was tuned a bit too aggressively or you just got unlucky on meth flow or fuel octane for a moment. It only takes a moment to blow up.

Mike

[derrick603]

Originally Posted by -Wingman-

The pistons are forged, how could this have happened?!

The pistons aren't forged, and even if they were, they're not forged out of adamantium.

[pgaplayerless]

that does not look like melted piston

[Killerfish2012]

Originally Posted by 135Pats

The sleeve damage makes me sad, was hoping you could "just" swap out the nuked piston. Man that crown and ring are just totally blown to pieces…Have you checked out the injector for that cylinder? I don't think I've come across this issue before, then again we don't see many outright blown N54s. This is pure 100% speculation on my part, but things could have gotten too hot due to a lack of meth and/or fuel in cylinder. Good luck finding a new motor, sorry for the loss man.

+1 on the meth flow theory. This would be one more in a list of quite a few that we've seen recently.

[135Pats]

Originally Posted by Killerfish2012

+1 on the meth flow theory. This would be one more in a list of quite a few that we've seen recently.

Here’s the thing though, if meth were to suddenly cease flow
1. One would hope the failsafe could anticipate and react quickly enough. OP what meth system were you running?
2. Were meth to stop spraying and the failsafe didn’t work, why would just cyl 2 get too hot? Would think all the cylinders would starve. Cyl 2 usually gets pretty decent meth flow too.
Odd stuff. Right as I’m about to jump to RBs and meth, I see this thread and get cold feet. Lame.