[asudhak]

I just replaced my 30k miles old set with NGK one step colders this weekend. Just regular maintenance, no misfires.

All plugs came out easily with the exception of cylinder 5 where I had to struggle to get it out.

I noticed lot of residue (not wet) in and around the spark plug tube.

Attached the image of the spark plug, all of them look pretty much the same way.

Is this normal wear, or does this indicate any leaks in the valve cover gasket or something else.

[dpaul]

Pretty common to have residue on the threads- could be from VC leak or slop from oil changes/top offs. Your pic was intended to illustrate the threads (I presume) and it's pretty hard to see if there might be black deposits on the plug tip - that would not be normal. However, what I can see looks OK.

You are "bone stock"? Why would you want to use colder plugs? They are not advised until you are making quite a bit of power.

[asudhak]

Originally Posted by dpaul

Pretty common to have residue on the threads- could be from VC leak or slop from oil changes/top offs. Your pic was intended to illustrate the threads (I presume) and it's pretty hard to see if there might be black deposits on the plug tip - that would not be normal. However, what I can see looks OK.

You are "bone stock"? Why would you want to use colder plugs? They are not advised until you are making quite a bit of power.

Thanks!
Yes i'm stock for now, but this in preparation for at least Stage 1+ in the coming months.

Interestingly I had asked this question https://www.e90post.com/forums/showthread.php?t=1828357 earlier, and the consensus was running these NGKs under stock setup doesn't cause harm.

[Dave92N54]

Tip of the plug is what matters for plug health, that looks like a good plug to me. The threads are as mentioned, valve cover leak or sloppy top off/fill up.

I ran 1 step colder plugs (NGK 97968) on a 100% stock car for almost a year with no issues.

[dpaul]

Originally Posted by asudhak

Thanks!
Yes i'm stock for now, but this in preparation for at least Stage 1+ in the coming months.

Interestingly I had asked this question https://www.e90post.com/forums/showthread.php?t=1828357 earlier, and the consensus was running these NGKs under stock setup doesn't cause harm.

I took a quick look at that thread, which has literally only one poster opining that colder plugs can be run "on a stock tune with no issues" and that poster is running RB turbos i.e. not a stock tune. That poster does not clearly indicate if he ran colder plugs in a stock motor for any length of time. Not exactly a consensus.

However, I agree that it is unlikely to cause harm, certainly not serious harm. A plug that is too hot would be way more dangerous. But colder is not optimal for a stock N54. It is true that some aspects of the N54 are poorly designed (injectors, water pump, oil pan and filter housing gaskets, valve cover/PCV system) but the BMW engineers did many things very well. I'm happy with their choice for spark plug heat range, even with modest increases in engine power (I'm at about 420 whp). Anyway, if the NGKs load up (carbon foul) you can put the old ones back.

[mweisdorfer]

The tips look normal to me

[Saif2018]

Originally Posted by asudhak

Thanks!
Yes i'm stock for now, but this in preparation for at least Stage 1+ in the coming months.

Interestingly I had asked this question https://www.e90post.com/forums/showthread.php?t=1828357 earlier, and the consensus was running these NGKs under stock setup doesn't cause harm.

OEM Bosch ones, (which don't need gapping) run fine upto at least 400whp or more, I'm running them on stage 1+ no issues.

There's virtually no benefit from running colder plugs at your power level or even stage 1+

I agree the Plugs look normal from I can see.

[srey]

Originally Posted by mweisdorfer

The tips look normal to me

That's what she said.

Sorry. Couldn't resist.