I was replacing spark plugs and found uneven wear. In picture #1-4 top to bottom in picture. The wear of them is in order of cylinders. Also it seems #3 & 4 are far worse.

Possibly is there something wrong with the coil pack delivering more juice to one side or the other? Thoughts answers?

Using magnecore wires. Just replaced with NGK Iridium in cold range.

 

the coils fire i think 1and 4 are on one coil and 2,3 are on the other. soooo don'think so . the coloring seems consistent yeah?

 

check the coil pack itself, ive heard you can develop rust on the points and not get a good "fire". apparently this is kinda common....?

 

Your #3 and #4 centre electrode wear are crazy. Those are huge gaps!

How was your MCS running?

My Densos wore heavy on the side electrods on #3 and #4. I'm running 4 prong JCW NGKs now. I'll take a peek at them at the end of summer.

Jeremy

 

if those came out of my motor, i'd scope the head to see what else is going on

they look eaten up, and the two most likely culprits are heat and shock - both arising from detonation or excessive cylinder pressures

it's a danger sign, and if you find the cause now you might save yourself a fair bit of pain

are the injectors all good? are the clean? are you running the stock MAP? i'd ask myself those questions and any others that might relate to early signs of damage in the combustion chambers...

better safe than sorry...got a mechanic that you trust? show them those plugs!

 

The car seemed to have low torque at launch. I have 44k on the car and ~36k on those plugs. It just felt sluggish, but no bad/odd symptoms (except failing tensioner, but that is a different issue).

If you really look at the plugs, 1-2 have the side electrode worn away, and plugs 3-4 have the center electrode worn away. 1-2 have a pocket worn out of the side electrode tip. There is no sign of anything catastrophic, the center electrodes are smoothly worn.

I thought Denso IK22 plugs were supposed to last longer and then did some reading that said 30k. So it was a good time replace plugs while doing a belt replacement. Note to self: check plugs every 10k.

Car is mapped, 15%+2%, ALTA intake. Always run 93 octane.

Now car runs perfect and launch is back to threshold tire squealing. (although I rarely drive 'fast')

 

You know what is funny you guys? I started posting a thread in here today, but opted to delete it concerning the same thing. I did an oil change and sparkplug change today. I had Bosch Platinum Plus 4s in mine. I started noticing a decrease in performance, so I ordered Denso IK 22s. Upon inspecting the old plugs today, cylinders 1 and 2, were okay looking, but cylinders 3 and 4's center electrodes were worn down to the point that it looked like they weren't even there.

CMT52663's post was kind of scaring me, but I have to remember that Bosch Platinum Plus 4's aren't that great of a sparkplug for a MINI. After the oil change and plug change, car seems to be running as spiffy as before.

 

How many miles on plugs?

 

A reduced interval change will always help!

Check out this thread. It seems I had similar wear to you actually, but not as bad(I guess I forgot about the centre electrode wear from a few months ago-hehe). See my post #9 and post#12 by Frenchie.

https://www.northamericanmotoring.co...spark+plug+gap

Jeremy

 

some guys may disagree, but 36,000 miles between changes for these peppy engines and these spark plugs is too many. Cylinders three and four may run a little hotter than the other two, but there are no white deposits on the plugs to indicate over heating or detonation. Number 4 shows a little blow by. Be sure to use correct torque when installing plugs and put a little bit of anti-seize on the threads. Whew, the threads are so dry!

and, fishey, thanks for posting a good photo so we can see them.

 

"The reason for the side wear on 1 and 2 is because these two fire from the side to the center electrode(backwards) the other two fire from the center to the side. This behavior is by design due to the DIS system (one coil fires two companion cylinders at the same time). Be advised that the plugs that fire from the side to center require, about 20% more energy to accomplish this task due to higher resistance when compared to the other two plugs."

So the wear pattern seems to make sense from this quote from your previous thread.

Those plugs were a ***** to get out, and were properly torqued in originally.

Anti-seize on threads? I was taught no lube on spark plugs by my father. Of course I am open to new methodology and my father was not always right and that was a long time ago.

 

My IK22's looked almost exactly the same as yours. #3 and #4 electrodes were gone. I was having bad misfire at high rpm and idle stumbles. I replaced mine with NGK Iridiums one step colder. What gap do you have your new plugs at?

 

I used stock from the box .8mm or ~.032.

 

There was roughly 17,000 miles on the Boschs.

 

good point on the absence of white deposits...

so is this erosion solely due to the electrical discharge?

i've a set of NGK R in front of me (the four prongs - BKR7EQUP) that came out at 40k miles and they are structurally perfect and have the same gap as when they went in.

 

The way you actually read a plug is with a magnifying glass and strong light. You need to be able to see the coloration of the metal parts along with the electrode and electrode base. If there is bluing at the base this indicates a very hot combustion temperature. Not necessarily lean. In some cases the use of different heat ranges in cylinder may be recommended. Not uncommon in performance engines you just don't normally hear about this on forums.

 

Exactly. Reading plugs is becomming a lost art.

From what I can see from the pics ( OP ), #3 & #4 look fairly normal for 17000 miles. The Denso, the same plug ( IK 22 ) I also use, is good for about 10k, not much more. The electrode is so fine that that the heat will degrade them faster than the NGK counter part. This is not to say you have a lean condition, the color of the #3 & #4 is tan not a whitish grey. As herbi points out, in his post, the color looks consistant.
Without the actual plug in hand to examin my opinion is pure speculation. In any case you need new plugs.

 

Someone mentioned anti-seize on threads of spark plugs. Opinions please.

Originally when I had the denso's put in I was told they last 50-60k, then I read somewhere 30k and said I had better change them. Now it seem realty is 15-20k. Although I am now using NGK iridiums, but will check more often.

Car is running best I think it ever has.

 

Plug life varies. For me its simple money math. If I change more often then the highest efficiency out of the engine will be gained. If it be power, millage or even lower emissions, it makes more sense to change plugs more often. Cheap performance part easy to change. IMO
I always use anti-seize on plugs and torque them to spec's. Not by feel!

 

I've never used anti-seize paste on plug threads before. 20-22 lbs for us into the aluminium cylinder head so no need to plus the spark plug tubes are seal out the elements.

I just checked my torque before a recent road trip and found cylinders 2 and 3 to be slightly under torqued.

Jeremy

 

I've always used just a touch of anti-seize when I change plugs. And always used a torque wrench too.

 

I have mixed feelings about anti seize on threads. if you plan on removing the plugs often (e.g. every 10k miles) I would recommend using anti seize with a copper base to promote conduction.

I also don't believe there is any advantage to replacing the original plugs with any other make or model especially single electrode!

I want to be clear, I am not putting anybody down for doing this but it is an unnecessary expense.....back to the question of anti seize.

The spark plug hole serves three purposes:
1. A method to mount the plug.
2. A heat sink to dissipate heat from the plug.
3. A path for the electrical current to return to ground.

In some instances anti seize can have a thermal insulating effect as well as an insulation effect on the electrical return path.

Porsche has a TSB out stating not to use anti seize on the plugs.....

Now the flip side.......the head is aluminum........the plugs are long life 100K miles (more like 50k in reality) this means that on a 200k mile vehicle the plugs would have been replaced anywhere from 2-4 times. But as stated before for those of you who will be pulling the plugs at 10K for whatever reason....now you are destroying the threads and should consider using anti seize. Lastly do not pull the plugs with the engine hot or the chance of damaging the threads will be greater.