[dzenno]

As I weed through all the threads and posts on colder and gapped plugs I realize that we probably need to put a plan in place and start some testing in the community to try to cover alternatives to stock. I am thinking of doing this myself as I've experienced misfires up top (6500rpm) which are 100% related to how much cylinder pressure I'm running and on my car it's always cylinder 5.

For those interested in participating I suggest they mention the plug they'll be testing here first and indicate all the details on the plug such as: manufacturer, material, gap.

For those that have already tested alternatives please post your findings here so we can have a single place to refer to for spark plug alternatives.

Many of you will say that I should stay with stock plugs as there have been a few cases of engine failure while running others. I've read through Enrita's thread and saw his plug. He was running low pump gas octane and 22-23 psi of boost with a cm7 nozzle meth at the airport strip and that was just a mistake and I really don't see how the stock plug would've saved the day there either. He mentioned that when the engine was pulled the rest of the plugs looked great. That in itself indicates that plugs weren't the cause of engine failure but fueling.

Post'em up! Let's find a working 1 step colder single electrode plug which we can gap when required. Multielectrode (like our stock plugs) can't be gapped.

[TurboBullett@Ambient Thermal Management]

Not related to the thread but I have read about your single cylinder misfire, and there's another thing you can check. I had a single cylinder miss on my old b5 s4 under load(at 400+ whp) that wouldn't change with coil, plug or injector swaps to other cylinders, the cause was a worn cam lobe on one of the valves!

Originally Posted by dzenno

As I weed through all the threads and posts on colder and gapped plugs I realize that we probably need to put a plan in place and start some testing in the community to try to cover alternatives to stock. I am thinking of doing this myself as I've experienced misfires up top (6500rpm) which are 100% related to how much cylinder pressure I'm running and on my car it's always cylinder 5.

For those interested in participating I suggest they mention the plug they'll be testing here first and indicate all the details on the plug such as: manufacturer, material, gap.

For those that have already tested alternatives please post your findings here so we can have a single place to refer to for spark plug alternatives.

Many of you will say that I should stay with stock plugs as there have been a few cases of engine failure while running others. I've read through Enrita's thread and saw his plug. He was running low pump gas octane and 22-23 psi of boost with a cm7 nozzle meth at the airport strip and that was just a mistake and I really don't see how the stock plug would've saved the day there either. He mentioned that when the engine was pulled the rest of the plugs looked great. That in itself indicates that plugs weren't the cause of engine failure but fueling.

Post'em up! Let's find a working 1 step colder single electrode plug which we can gap when required. Multielectrode (like our stock plugs) can't be gapped.

[enrita]

As mentioned by Dzenno i run the NGK iridium plugs from the Mini Cooper S
5992 NGK Spark Plug. Part# ILZKBR7A-8G
Those were gapped little closer from my shop (dont know how much).

I have never noticed any issue with them with cold/warm start and the car was running fine.

I still have a set so i might put them back on later on. OEM ones are working fine for me at the moment so i dont feel any need right now.

[dyezak]

Because spark ignited direct injection is somewhat new (diesel direct injection without sparkplugs isn’t new); fiddling with the plugs is going to be a tricky proposition. The plug’s proximity to the injector is of concern. If your new plug has a geometry that interferes with the spray pattern of the injectors you may notice negative effects. If you reference page 32 of the BMW 2007 N54 Engine Management packet you will see the injector spray pattern in relation to the spark plug and the permitted spray divergence. If you go down to page 39 you will see what happens when the spray pattern hits the plugs…basically the plugs melt.

Now adding in new plugs not designed for this engine won’t change the DI spray pattern, but if it moves the plug into the standard spray pattern I’d expect to see detonation, and the associated damage.

I’m not saying that finding a better plug is impossible, just difficult due to there not being a lot of spark ignited direct injection systems out there. If I were you I’d start looking at other spark ignited direct injection systems that are already producing more power than the N54 engine is stock. See what kind of plugs those engines are running, their concerns with plug intrusion, and how enthusiasts are perceiving the ignition system on that engine.

I’d start by looking at the Ford Taurus SHO with the v6 twin turbo eco-boost engine. 380hp stock, so their cylinder pressures are likely higher than an N54 stock and would need a cooler plug than we use.

[dyezak]

Just to help a bit more: http://www.rockauto.com/catalog/x,ca...,parttype,7212

[jpsimon]

I ran the NGK plugs for a week or so and noticed more timing drops than with the stockers... took em out and sold them.

[Elie335]

I don't understand why you guys keep switching plugs and wasting money, IT have been proved before that aftermarket plugs aren't working well...

[dyezak]

Originally Posted by Elie335

I don't understand why you guys keep switching plugs and wasting money, IT have been proved before that aftermarket plugs aren't working well...

Elie, so far that statement is true. However there *will* become a point at which the stock plugs reach their limit. Usually you reach the heat capacity of the plugs and they get too hot causing pre-ignition. At that point you usually go to a cooler heat range plug to allow you to properly control ignition again.

The OP believes he may have reached that point...and who are we to tell him otherwise? He makes more power than me... And more power than most people here.

[dyezak]

Funny how Track rat and I both mention pre-ignition due to heat range being exceeded 2min apart from each other...

[dzenno]

Originally Posted by TTurboBullett

Not related to the thread but I have read about your single cylinder misfire, and there's another thing you can check. I had a single cylinder miss on my old b5 s4 under load(at 400+ whp) that wouldn't change with coil, plug or injector swaps to other cylinders, the cause was a worn cam lobe on one of the valves!

Man that must've been hard to find...I don't think thats the case here as the misfire is always at 6500rpm...peak cylinder pressures are way below that, at peak engine torque and the car can run any amount of boost there up to 19psi tested so far with upgraded turbos, without any slightest hesitation...

Originally Posted by enrita

As mentioned by Dzenno i run the NGK iridium plugs from the Mini Cooper S
5992 NGK Spark Plug. Part# ILZKBR7A-8G
Those were gapped little closer from my shop (dont know how much).

I have never noticed any issue with them with cold/warm start and the car was running fine.

I still have a set so i might put them back on later on. OEM ones are working fine for me at the moment so i dont feel any need right now.

I wouldn't bother touching plugs in your case as your car doesn't have any issues at the moment...

Originally Posted by dyezak

Because spark ignited direct injection is somewhat new (diesel direct injection without sparkplugs isn’t new); fiddling with the plugs is going to be a tricky proposition. The plug’s proximity to the injector is of concern. If your new plug has a geometry that interferes with the spray pattern of the injectors you may notice negative effects. If you reference page 32 of the BMW 2007 N54 Engine Management packet you will see the injector spray pattern in relation to the spark plug and the permitted spray divergence. If you go down to page 39 you will see what happens when the spray pattern hits the plugs…basically the plugs melt.

Now adding in new plugs not designed for this engine won’t change the DI spray pattern, but if it moves the plug into the standard spray pattern I’d expect to see detonation, and the associated damage.

I’m not saying that finding a better plug is impossible, just difficult due to there not being a lot of spark ignited direct injection systems out there. If I were you I’d start looking at other spark ignited direct injection systems that are already producing more power than the N54 engine is stock. See what kind of plugs those engines are running, their concerns with plug intrusion, and how enthusiasts are perceiving the ignition system on that engine.

I’d start by looking at the Ford Taurus SHO with the v6 twin turbo eco-boost engine. 380hp stock, so their cylinder pressures are likely higher than an N54 stock and would need a cooler plug than we use.

Great post, thanks!

It might be the injector having a bad spray pattern, maybe it relates to rail fuel pressure and ignition timing when the spark fires...

Originally Posted by dyezak

Just to help a bit more: http://www.rockauto.com/catalog/x,ca...,parttype,7212

Cool..

[dzenno]

Originally Posted by dyezak

Elie, so far that statement is true. However there *will* become a point at which the stock plugs reach their limit. Usually you reach the heat capacity of the plugs and they get too hot causing pre-ignition. At that point you usually go to a cooler heat range plug to allow you to properly control ignition again.

The OP believes he may have reached that point...and who are we to tell him otherwise? He makes more power than me... And more power than most people here.

I'm not trying to get a colder plug as I'm not trying to solve pre-ignition...i'm trying to solve a misfire issue which could be the injector and that will be dealt with first...i'm really talking about solving my issue IF it isn't solved after changing the injector on that cylinder...if the injector doesn't fix it then the next thing I'm thinking is a plug closes to stock as possible just single not multi-electrode (not colder as that's not required) where it can be gapped just a tiny bit from stock to see if things change..

Originally Posted by TrackRat

If the OE plugs were too hot there would be excessive erosion, blistering and no color. If there was pre-ignition the electrodes would melt as shown in the sparkplug link I posted above.

Electrode melted and was blistered on enrita's plug after he had his ringland fail but we already know that in that particular case it was inadequate octane for 22-23psi of boost with TD Stage 2 turbos...

Ellie, I don't "want to" run a different plug...i'm NOT looking to make more power than I can with the stock plug...i'm trying to find the cause to what at the moment looks like a cylinder pressure related misfire...that'll be even more confirmed if the issue is still present after changing the faulty rear o2 sensor on bank2 (which is the one misfiring) and if required after that, also changing the injector on cylinder 5...

Then I'll be all over aftermarket single-electrode plugs, same heat range, just single-electrode so I can gap them...multi-electrode plugs cannot be properly gapped..

[R1000K3]

You can always close the gap a bit on stock plugs and check what happens. This would be interesting since we don't know for sure if the Okada's provides more spark energy on N54.

[dzenno]

Originally Posted by R1000K3

You can always close the gap a bit on stock plugs and check what happens. This would be interesting since we don't know for sure if the Okada's provides more spark energy on N54.

That's the thing about multi-electrode plugs, you can't gap them properly as the other electrodes are in the way..

I don't doubt the Okada coils provide more spark energy and more consistent secondary spark...testing with/without those will have to wait until this is resolved though..

[R1000K3]

I don't see how the other electrodes are in the way. It should be possible to gap them by using a wire as a tool for the desired gap. I haven't done it myself though.

[dzenno]

Injector on cyl 5 changed and coded as well as rear o2 sensors, misfire on cyl 5 stll there...this is now on Cobb with a jb+ on top which I have set to the min setting just to add about 2.75psi in top if Cobb stg1 to trigger the misfire...off the shelf cobb stg1 won't misfire as it runs only 12.5psi at 6500rpm...I can also now log everything using BT at a boost that causes a misfire including any ignition and fueling values on all cylinders...

I'm officially out of options...I did have a low fuel pressure sensor code today which was a first...I'll watch if it comes back but this was low pressure fuel related it wouldn't be isolated to cyl 5 only I don't think...don't think I need other colder/gapped plugs as it's always cyl 5 misfiring especially given brand new plugs, coils and injector...

Cam bearing on cyl 5 is now the only option but how/why would that go? Whats the right procedure to check it?...any other opinions?? If it is cam lobe why doesn't it misfire on cyl 5 when boost is just reduced 1psi below this misfire threshold...I raise it back it misfires, move it down it goes away

[mycoupe]

Originally Posted by dzenno

Injector on cyl 5 changed and coded as well as rear o2 sensors, misfire on cyl 5 stll there...this is now on Cobb with a jb+ on top which I have set to the min setting just to add about 2.75psi in top if Cobb stg1 to trigger the misfire...off the shelf cobb stg1 won't misfire as it runs only 12.5psi at 6500rpm...I can also now log everything using BT at a boost that causes a misfire including any ignition and fueling values on all cylinders...

I'm officially out of options...I did have a low fuel pressure sensor code today which was a first...I'll watch if it comes back but this was low pressure fuel related it wouldn't be isolated to cyl 5 only I don't think...don't think I need other colder/gapped plugs as it's always cyl 5 misfiring especially given brand new plugs, coils and injector...

Cam bearing on cyl 5 is now the only option but how/why would that go? Whats the right procedure to check it?...any other opinions??

You would most likely have to use plastigauge on it and compare what you find to the specs for it. If it's the cam lobe, check the clearance like doing a valve adjustment. Those are my best guesses for that issue.

As for the low fuel pressure...could that have been caused by upping the boost on the COBB tune? Since it's not an "active" tune, like autotunes, could it be that with the extra psi you pushed it past the fuel limits of the map???

BTW...check the PCV thread

[dzenno]

Misfire is there same boost with procede, jb4 and Cobb stg1 with jb+

[dzenno]

Think I narrowed it down further, 1st and 2nd gear never miss, 30 pulls each and not a single miss 19psi tapering to 16psi at 6500rpm...3rd gear pull starting at high RPMs around 5k rpm will never miss either...it will miss if I start the pull at 4k rpm and below and hold to 6500rpm...this has to be fuel "system" related, thoughts?

I got the 29F3 code yesterday (LPFP fuel pressure sensor) yesterday but not sure that would be the cause...

[dyezak]

Can you post up some logs for us to review (CSV perhaps)?

[dyezak]

Oh, and have you cleaned your intake valves? Just a completely random thought...

[R1000K3]

Originally Posted by dzenno

Think I narrowed it down further, 1st and 2nd gear never miss, 30 pulls each and not a single miss 19psi tapering to 16psi at 6500rpm...3rd gear pull starting at high RPMs around 5k rpm will never miss either...it will miss if I start the pull at 4k rpm and below and hold to 6500rpm...this has to be fuel "system" related, thoughts?

I got the 29F3 code yesterday (LPFP fuel pressure sensor) yesterday but not sure that would be the cause...

I would check if there is any difference between gears. If misfires are more common on higher gears it indicates a fuel supply problem. In case it is the same on all gears it should be something that is not fuel supply dependent.

If the cam lobes can bee seen in the N54 engine, it will be easy to see if a lobe is worn just by looking on it. As soon as there is a visible sign of wear on a cam lobe it will go south very quick.

[enrita]

Dzenno: when we logged injectors yours were maxed at 15.5-16 psi while mine had still a 10% ?