OK to Clean N54 Carboned up Spark Plugs?

Boland01 · 12-07-2016, 08:27 AM

Our 2007 335i had injectors #1 and #3 stick open and cause the car to run rich. I ended up switching out all six injectors to index #12 ones and coding with INPA.

The spark plugs have 7K miles on them. When I pulled them #1 and #6 spark plugs they had lots of carbon build up on them. I went ahead and used sandpaper and gasoline to clean the electrodes off.

In your opinion is this still an acceptable thing to do? I know the N54 engine can be pretty finicky. Running it in map 0 this week just to make sure there are no issues. Haven't gone back to map 5 yet.

Jaronbwall · 12-07-2016, 08:55 AM

I would have used a spark plug cleaning device. It's hooked up to compressed air and uses light sand blasting to clean the entire plug. We used them all the time on our 2-stroke dirt bikes.

r4dr · 12-07-2016, 12:47 PM

Spark plugs for these cars are damn cheap, I would just get a new set from RockAuto or something

Antetokounmpo · 12-07-2016, 03:22 PM

Quote:

Originally Posted by r4dr

Injectors for these cars are damn cheap, I would just get a new set from RockAuto or something

$200 is cheap for an injector? Even when they used to be $120 that was still a lot for an injector compared to most cars.

r4dr · 12-07-2016, 04:14 PM

Wow I totally blanked, I meant spark plugs.

Yeah, injectors are not cheap by my standards.

JM98 · 12-07-2016, 07:53 PM

The cost of 2 new plugs vs having to pull the car apart again for a misfire is well worth it

r4dr · 12-08-2016, 11:16 PM

Quote:

Originally Posted by JM98

The cost of 2 new plugs vs having to pull the car apart again for a misfire is well worth it

Going down that logic, might as well replace all 6 while you're in there. The labor is the same and it's just $40 more.

JM98 · 12-09-2016, 06:45 AM

Quote:

Originally Posted by r4dr

Going down that logic, might as well replace all 6 while you're in there. The labor is the same and it's just $40 more.

Exactly. It can be a slippery slope though.... this logic has me doing a valve cover gasket, OFHG, walnut blast, serpentine belt, plugs, coolant flush, and oil change all at once this weekend. Pain in my ass.

Wolf 335 · 12-09-2016, 06:52 AM

If he is able to clean it of without damaging the spark plug, there is nothing wrong with that.

That plug will still function normally.

So if you want to throw money away get new plugs. If the one you cleaned works fine, why change it?

Boland01 · 12-09-2016, 08:34 AM

We've had a couple misfires- the car goes briefly into limp mode. Crazy thing is there are no codes when we check it. I've already replaced the coils and injectors as well as the mosfets. We have both the torque app and JB4 to check it.
The only thing that is original now are the oxygen sensors and cleaned spark plugs (with 8K on them). I'm just going to go ahead and get six new plugs.

12-09-2016, 09:03 AM

Quote:

Originally Posted by Boland01

We've had a couple misfires- the car goes briefly into limp mode. Crazy thing is there are no codes when we check it. I've already replaced the coils and injectors as well as the mosfets. We have both the torque app and JB4 to check it.
The only thing that is original now are the oxygen sensors and cleaned spark plugs (with 8K on them). I'm just going to go ahead and get six new plugs.

What plugs specifically and what gap are you running them at?

Mod list?

Boland01 · 12-09-2016, 09:56 AM

Quote:

Originally Posted by FCobra94

What plugs specifically and what gap are you running them at?

Mod list?

Mods are catless downpipes, CRX racing FMIC, JB4 map2 and DCI. 93 octane gas here too. Plugs are the standard Bosch ones.

12-09-2016, 10:37 AM

Quote:

Originally Posted by Boland01

Mods are catless downpipes, CRX racing FMIC, JB4 map2 and DCI. 93 octane gas here too. Plugs are the standard Bosch ones.

Try a set of 95770s this time instead:
http://www.ebay.com/itm/271955436860

The colder heat range may help with your misfires; it certainly won't hurt in any way so it's a win/win regardless.

JM98 · 12-09-2016, 11:49 AM

Point proven. Just replace em

12-07-2016, 08:27 AM	#1
Boland01 Lieutenant 149 Rep 460 Posts Drives: 2010 535ix, 2008, 2007 335i Join Date: Sep 2013 Location: Magnolia, TX iTrader: (0)	OK to Clean N54 Carboned up Spark Plugs? Our 2007 335i had injectors #1 and #3 stick open and cause the car to run rich. I ended up switching out all six injectors to index #12 ones and coding with INPA. The spark plugs have 7K miles on them. When I pulled them #1 and #6 spark plugs they had lots of carbon build up on them. I went ahead and used sandpaper and gasoline to clean the electrodes off. In your opinion is this still an acceptable thing to do? I know the N54 engine can be pretty finicky. Running it in map 0 this week just to make sure there are no issues. Haven't gone back to map 5 yet.
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12-07-2016, 08:55 AM	#2
Jaronbwall Driving cars and riding bikes really fast 285 Rep 1,002 Posts Drives: 2009 335i Join Date: Sep 2014 Location: Indianapolis iTrader: (0)	I would have used a spark plug cleaning device. It's hooked up to compressed air and uses light sand blasting to clean the entire plug. We used them all the time on our 2-stroke dirt bikes. __________________ 335i, sport pkg, 3 pedals, Blacked out, LED markers, OZ Ultraleggera wheels, Firestone Indy 500s, x-pipe, vibrant 1792, PE mod MHD stage 2+, BMS DPs, ARM charge pipe, Tial BOV, ARM FMIC, dual cone, CSF radiator, M3 control arms, sways, HAWK pads. https://www.strava.com/athletes/8309149 Follow me on Strava
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12-07-2016, 12:47 PM	#3
r4dr First Lieutenant 172 Rep 392 Posts Drives: various BMWs Join Date: Oct 2015 Location: Seattle, WA iTrader: (0)	Spark plugs for these cars are damn cheap, I would just get a new set from RockAuto or something Last edited by r4dr; 12-07-2016 at 04:14 PM.. Reason: Spark plugs not injectors, doh
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12-07-2016, 04:14 PM	#5
r4dr First Lieutenant 172 Rep 392 Posts Drives: various BMWs Join Date: Oct 2015 Location: Seattle, WA iTrader: (0)	Wow I totally blanked, I meant spark plugs. Yeah, injectors are not cheap by my standards.
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12-09-2016, 06:52 AM	#9
Wolf 335 Brigadier General 2341 Rep 3,539 Posts Drives: 2007 E92 335i Join Date: Aug 2012 Location: GTA - Greater Toronto Area iTrader: (0)	If he is able to clean it of without damaging the spark plug, there is nothing wrong with that. That plug will still function normally. So if you want to throw money away get new plugs. If the one you cleaned works fine, why change it?
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12-07-2016, 07:53 PM	#6
JM98 Lieutenant 391 Rep 532 Posts Drives: 2009 135i Join Date: May 2016 Location: SoCal iTrader: (0)	The cost of 2 new plugs vs having to pull the car apart again for a misfire is well worth it
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12-09-2016, 08:34 AM	#10
Boland01 Lieutenant 149 Rep 460 Posts Drives: 2010 535ix, 2008, 2007 335i Join Date: Sep 2013 Location: Magnolia, TX iTrader: (0)	We've had a couple misfires- the car goes briefly into limp mode. Crazy thing is there are no codes when we check it. I've already replaced the coils and injectors as well as the mosfets. We have both the torque app and JB4 to check it. The only thing that is original now are the oxygen sensors and cleaned spark plugs (with 8K on them). I'm just going to go ahead and get six new plugs.
	Appreciate 0 Quote

12-09-2016, 11:49 AM	#14
JM98 Lieutenant 391 Rep 532 Posts Drives: 2009 135i Join Date: May 2016 Location: SoCal iTrader: (0)	Point proven. Just replace em
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