How many miles on these? 328i plugs

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OVERKILL

OVERKILL

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Engine has 256,000Km's on it.

Pulled these today because the car was "bucking" under load (like when climbing a steep hill and it wanted to hold the gear), which I assumed was a probably a misfire.

Issue is now gone since I changed the plugs. Since I don't have the service documentation for this car, I don't know when, or if, these were ever changed.

328iplugs01.jpg

328iplugs02.jpg

328iplugs03.jpg

328iplugs04.jpg

328iplugs05.jpg


Comments are welcome.

Oh, and I put regular NGK "G-Power" fine electrode Platinum plugs back in. Plugs on this car are like a 20 minute job, so I'm not concerned about having to do them on a slightly shorter interval going forward.
 
Originally Posted By: Coprolite
What is the gunk on the wire end of the first plug?


Appears to be dielectric grease.
 
Those don't appear to be too old, however they do appear to have been in a hot running engine based on the overall grey deposits (instead of tan) and maybe the heat discoloration on the threads.

I don't know if your car has an EGR system, but if it does that could explain the high heat if its not working.

The bucking you experienced could have been pinging/detonation as a result?
 
Originally Posted By: SOHCman
Those don't appear to be too old, however they do appear to have been in a hot running engine based on the overall grey deposits (instead of tan) and maybe the heat discoloration on the threads.

I don't know if your car has an EGR system, but if it does that could explain the high heat if its not working.

The bucking you experienced could have been pinging/detonation as a result?



I've never had tan plugs on any of my EFI engines, they are always pretty white. These are no different in that regard.

Yes, it has EGR, and considering how well it did on its E-test, I'm going to say it is working properly.

These plugs, like on a Modular, are located down a 6" deep plug well, so I'm quite sure they get very hot.
 
Consider the Denso Iridiums for next time if you don't mind changing them a bit more often -- the super-sharp electrode is unmatched from any other manufacturer.

Your plugs don't look too bad, actually.
 
Originally Posted By: dparm
Consider the Denso Iridiums for next time if you don't mind changing them a bit more often -- the super-sharp electrode is unmatched from any other manufacturer.

Your plugs don't look too bad, actually.


No, I didn't think they looked bad either, just worn. Which I think explains the misfire that is now no longer occurring.

Oh,and it is hard to tell from the pics, but the centre electrode is a little recessed into the porcelain on them as well.
 
EGR and VANOS seals are to blame. The former can be cleaned, I have had excellent results with Seafoam (tube went from being 75% blocked to fully clean, like new). It takes some time but is much better than the cost of a.replacement, and even if you do have to replace it at least you are halfway done.
The VANOS seals are something that I cannot in good conscience recommend replacing with OEM. There are multiple aftermarket kits that use extremely high quality parts and replace all of the "trouble spots" in the system.
I used one such kit 3-4yrs ago, and there was an immediate effect... The car felt alive again, no more idle issues, better economy, and a significant power bump... Above 3500rpm the car felt like it gained back 25hp or more, as well as being much more willing to rev. The difference was as significant as adding a 10lb flywheel and underdrive pulleys. It was not subjective, it was irrefutable. A highway.onramp where I would "test" the motor, for the month prior to the VANOS kit I would be at 73-75mph immediately at the highway (from a stop, full acceleration and shifting at redline but no clutch dumping). After replacement, I was at 83mph with no other changes. It is not a long onramp, but it is completely straight and there is a light immediately before it so you are already lined up, and it is a very low traffic area so 9/10 there is noteven anyone on the hwy, and if there is someone around I can just circle around and wait.
After the supercharger install, and all of the other stuff (inc: 3.23 LSD, wider tires, 350lbs+ weight loss, 6spd swap, aero parts, wide fenders for 11" wide rears, and all the other go-fast goods), full throttle on the same on ramp my first few tries was over 115mph...

So, you would be doing yourself a favor to look into each. You might check the.PCV system, IACV, and SAP too... Plus a good TB cleaning and MAF cleaning.
 
Originally Posted By: GMBoy
I always thought only Bosch made 4 prong plugs. Learn something new everyday..


I know eh? LOL!
 
Originally Posted By: OVERK1LL

the centre electrode is a little recessed into the porcelain on them as well.


I'd say that right there is why you were having problems. If center electrode is recessed, spark has to jump much further, and around an obstacle.

Good thing these were changed when they were
 
Originally Posted By: Joseph_S37
Originally Posted By: OVERK1LL

the centre electrode is a little recessed into the porcelain on them as well.


I'd say that right there is why you were having problems. If center electrode is recessed, spark has to jump much further, and around an obstacle.

Good thing these were changed when they were


Exactly what I was thinking
thumbsup2.gif


Also, the electrodes are worn quite a ways in (I assume they are flat across when new like the Bosch ones are, while these have significant curves into each of the electrodes, as you can see in the pic) making me think they have a fair number of miles on them.
 
Originally Posted By: OVERK1LL
Originally Posted By: GMBoy
I always thought only Bosch made 4 prong plugs. Learn something new everyday..


I know eh? LOL!


NGK makes 1, 2, 3, and 4 ground plugs. The even make them with all 3 grounds connected with a triangle. The difference is that they are all for specific engines. The Bosch "+" series were marketed as a design for all engines.

I'd bet the plug design you pulled out are specific to your BMW.
 
Stay away from those 4 prong plugs, lots of German cars don't like them.

Stock is the way to go.

Other than that they look fine.
 
Originally Posted By: hattaresguy
Stay away from those 4 prong plugs, lots of German cars don't like them.

Stock is the way to go.

Other than that they look fine.



Pretty much every German car made within the last 5 years came with 4-lash as OEM....
 
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