[goj]

Originally Posted by G.Newt

Where have we seen leaky injectors before? *coughs in N54*
BMW just can't get an engine all the way right.

How is this a sign of bmw not producing an engine "all the way right?"

We accept the fact that heavily tuning our engines may in fact have catastrophic consequences even if we all hope it never happens.

[Sgm123]

Do you guys think it may be worth borescoping when plugs are changed just to see if it looks like any cylinders are running rich, scoring etc.

[kern417]

Originally Posted by Stu101

Do you guys think it may be worth borescoping when plugs are changed just to see if it looks like any cylinders are running rich, scoring etc.

Obviously It wouldn't hurt but unless you're doing it once a week don't expect it to save you from this sort of issue. Best bet is to pay attention to how the car is running, run logs, etc. There are other indicators of stuck injectors.

I remember reading a lot of threads of stuck/failed injectors on here when I was doing initial research. I feel like we haven't heard much recently but it does seem to be somewhat of an issue.

[Sgm123]

What signs do you look for on the logs pretty new to
All this. Is it a consistent timing issue on a set cylinder or something? Thanks

[kern417]

Originally Posted by Stu101

What signs do you look for on the logs pretty new to
All this. Is it a consistent timing issue on a set cylinder or something? Thanks

You may see some knock/timing adjustments, but I'd look at fuel trims and AFRs more for potential fueling issues.

[sspade]

Note to self: Running a 93 octane tune on 91 pump gas is a terrible idea. No matter how much snake oil you add.

[eluded]

Originally Posted by sspade

Note to self: Running a 93 octane tune on 91 pump gas is a terrible idea. No matter how much snake oil you add.

Yeah bm3 runs at the edge of timing for your octane.

[Denys_BMW]

"...BM3 Stage 2 (93oct) tune on 91 and using some pretty heavy (+30pts) octane booster..." not good idea to do like this.

[Dyna+]

Originally Posted by sspade

Note to self: Running a 93 octane tune on 91 pump gas is a terrible idea. No matter how much snake oil you add.

#TRUTH....

Well I hit the cyl with a “bottle brush” hone and they have a nice cross hatch, got a ton of goodies coming for the build now.

FYI - Finding main bearings for this is a effing NiGhTmArE!!! Got the crank decoded and have the color codes but none of the dealers know how to look them up or they are showing discontinued already...

[G.Newt]

Originally Posted by goj

How is this a sign of bmw not producing an engine "all the way right?"

We accept the fact that heavily tuning our engines may in fact have catastrophic consequences even if we all hope it never happens.

This isn't the first report. Has happened on stock motors as well.

[Dyna+]

☝️ He ain’t wrong...

I’ll also add that there were 0 physical signs of pre detonation in my case so it’s hard to believe it was tune related

Cyl 5 was definitely being over fueled to say the least...

[weehe126]

Isn't cylinder 5 the closest to the hpfp? I have heard C5 being the issue most often if there is an issue.

[JD11937]

Originally Posted by Dyna+

☝️ He ain’t wrong...

I’ll also add that there were 0 physical signs of pre detonation in my case so it’s hard to believe it was tune related

Cyl 5 was definitely being over fueled to say the least...

Any early warning signs we can look out for? How did that plug look?

[BMWILUVU]

It looks like just a manufacture defect or weakness combined with running high boost on a cast piston. The two factors converged. There is no scoring of the cylinder or anything showing foreign matter and no detonation. I can't see cylinder 5 closest to hpfp having been a factor either since fuel is nearly in-compressible.

[Dyna+]

Originally Posted by JD11937

Any early warning signs we can look out for? How did that plug look?

Seeing as how the wife has a bone stock 2016 340i too LOL ...I wish there was but this just happened all of a sudden.

Like the other guy said probably a number of factors converging to create “perfect storm”

[goj]

Originally Posted by G.Newt

This isn't the first report. Has happened on stock motors as well.

All the reports I've seen on bimmerpost at least are regarding non-stock engines. I think there was one on a non-US car but not sure.

Seems like a pretty low failure rate but maybe you have more information from another source that I'm not aware of.

[eluded]

Originally Posted by Dyna+

Seeing as how the wife has a bone stock 2016 340i too LOL

She has one too ?

"Its gonna blow up if you touch it"
- my wife

[weehe126]

Looking at the pics again I'm pretty sure the lighter color on C5 is actually due to the oil, not fuel. You could always have the injectors tested.

[Dyna+]

Originally Posted by weehe126

Looking at the pics again I'm pretty sure the lighter color on C5 is actually due to the oil, not fuel. You could always have the injectors tested.

Yes I was going to have them all tested. There’sa shop in town (kinda) that’s I’ll take them to. Will post the results when I get them.

[Dyna+]

Got the first round of goodies today

Time to get the rebuild on the way

[Mr. 340]

Originally Posted by Dyna+

Got the first round of goodies today

Time to get the rebuild on the way

Nice man. Are those the 82mm or 82.5mm pistons? And what rod bearings did you get? Do they come with the coating that the original ones come from the factory?

[340iGUY]

Wow.
Are you a mechanic?
How did you know how to disassemble this?