Spark plug question

Lt. Leary · 04-26-2018, 04:16 PM

I was driving around town the other day and probably floored it a bit too much getting on the interstate. Heard a small pop, the engine started running rough and the check engine light came on. Once I was able to get off the road, I turned my engine off for a few minutes and it came back to life with the engine light off and the engine was running smoothly. I ran my OBD2 and got a fault code for a misfire in #5, which would either be bad plugs or a bad coil. I've only had my car for a year and hadn't changed the plugs yet, so I ordered 6 and started replacing them all today. When I got to #2, there was a small amount of crud at the tip, maybe oil? However, when I got to #3, there was quite a bit of oil covering the threads of the plug. I've never changed a set of plugs before, so I don't know if this is expected or not. I'm expecting not since none of the other plugs had the same problem. Any thoughts?

2008 BMW 135i coupe - N54 engine

BimmerAg · 04-26-2018, 05:00 PM

Oil on/around the plugs can be due to a valve cover gasket leak. Was there any oil or grime in the spark plug tube?

Lt. Leary · 04-26-2018, 09:38 PM

Yes, there was some grime in several of the spark plug tubes.

BimmerAg · 04-27-2018, 08:57 AM

Yep, sounds like the beginnings of a valve cover gasket leak

Lt. Leary · 04-27-2018, 12:44 PM

Thanks for your advice. Got a call out to my local mechanic.

1mang · 05-01-2018, 02:16 PM

N54 plastic valve cover is known to crack so you might wanna check that out since you would be doing valve cover gasket anyways.

04-26-2018, 04:16 PM	#1
Lt. Leary New Member 3 Rep 5 Posts Drives: 2008 135i Coupe Join Date: Dec 2016 Location: Charlotte, NC iTrader: (0)	Spark plug question I was driving around town the other day and probably floored it a bit too much getting on the interstate. Heard a small pop, the engine started running rough and the check engine light came on. Once I was able to get off the road, I turned my engine off for a few minutes and it came back to life with the engine light off and the engine was running smoothly. I ran my OBD2 and got a fault code for a misfire in #5, which would either be bad plugs or a bad coil. I've only had my car for a year and hadn't changed the plugs yet, so I ordered 6 and started replacing them all today. When I got to #2, there was a small amount of crud at the tip, maybe oil? However, when I got to #3, there was quite a bit of oil covering the threads of the plug. I've never changed a set of plugs before, so I don't know if this is expected or not. I'm expecting not since none of the other plugs had the same problem. Any thoughts? 2008 BMW 135i coupe - N54 engine
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04-26-2018, 05:00 PM	#2
BimmerAg Lieutenant 425 Rep 545 Posts Drives: 2011 135i Join Date: May 2017 Location: San Antonio, TX iTrader: (0)	Oil on/around the plugs can be due to a valve cover gasket leak. Was there any oil or grime in the spark plug tube? __________________ 2011 BMW 135i ///M-Sport, DCT Bilstein B12 kit, Dinan camber plates, M3 front control arms, Whiteline poly RSFB, MHD Stage 1, cp-e Charge Pipe, H&R Front sway bar, BMW performance diffuser
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04-27-2018, 08:57 AM	#4
BimmerAg Lieutenant 425 Rep 545 Posts Drives: 2011 135i Join Date: May 2017 Location: San Antonio, TX iTrader: (0)	Yep, sounds like the beginnings of a valve cover gasket leak __________________ 2011 BMW 135i ///M-Sport, DCT Bilstein B12 kit, Dinan camber plates, M3 front control arms, Whiteline poly RSFB, MHD Stage 1, cp-e Charge Pipe, H&R Front sway bar, BMW performance diffuser
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05-01-2018, 02:16 PM	#6
1mang Private First Class 36 Rep 127 Posts Drives: 135i Join Date: Jun 2014 Location: Bay Area, CA iTrader: (0)	N54 plastic valve cover is known to crack so you might wanna check that out since you would be doing valve cover gasket anyways.
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04-26-2018, 09:38 PM	#3
Lt. Leary New Member 3 Rep 5 Posts Drives: 2008 135i Coupe Join Date: Dec 2016 Location: Charlotte, NC iTrader: (0)	Yes, there was some grime in several of the spark plug tubes.
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04-27-2018, 12:44 PM	#5
Lt. Leary New Member 3 Rep 5 Posts Drives: 2008 135i Coupe Join Date: Dec 2016 Location: Charlotte, NC iTrader: (0)	Thanks for your advice. Got a call out to my local mechanic.
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