Error code P0303, #3 engine misfire

stanger · 04-10-2011, 10:50 PM

So I know that Cylinder #3 is misfire. I just recently replaced the plugs with the autolite iridiums, and the air cleaner. Ran awesome for few days, then it started to have a very rough idle at a stop. I tried to remove the plug, look at it and reinstall it, same issue, same cylinder. So I bought another plug, just to try and see if this fixed the problem, then I was going to check the coils by switching them, plugs were in store, Coils is special order. I first tried the spark plug and surprisingly it fixed the problem. So it must be a bad plug (New one), right? I mean, when a coil goes bad, can it send to much charge to the plug and ruin them? I know this may be a stupid question, but just wanted to ask before I purchase 6 coils, might as well do all if I do them. I have a long trip planne this Sat, so ......
Thanks for your replys

Titanium3Series · 04-11-2011, 11:00 AM

Why would you purchase 6 coils when you only have a single misfire? what i would do is take the number 3 coil and move it to 4, 5 or 6 cyclinder or whichever one and see if the misfire will jump to the other cylinder once the car is running and a cycle being completed. IF the misfire jumps then most likley you have a bad coil.

OR test the resistence of the coil if you can find the values

fdriller9 · 04-11-2011, 11:05 AM

On an 06 I would probably replace all coils too.....just for peace of mind.

Steve-o · 04-11-2011, 08:47 PM

Quote:

Originally Posted by *********

On an 06 I would probably replace all coils too.....just for peace of mind.

The benefit of coil overs is that when you have a problem like this you can replace just the single coil. The downside is they are generally more expensive if you have to replace the whole set in comparison to a traditional coil pack. However, just because his coils are OE on a 2006 doesn't suggest he should replace the lot. That would honestly be a huge waste of money, albeit you can find them fairly inexpensive some places. For example here you can get them for my e90 sedan for 29.99 a piece. Like the old saying goes, don't fix it if it ain't broke.

le0.br4zuc4 · 10-13-2014, 12:01 PM

I have a 07 335i, 80k miles on it. I don't drive a lot, usually go to work on my bike. Thursday I got the P0303 code as well and car is misfiring. I will order the spark plugs and the coil as well. At 80K miles, should I replace the 1 coil or should I replace them all for peace of mind? Since I'm going to be working on replacing plugs and at least 1 coil, anything else I should replace while I'm working on that?

04-10-2011, 10:50 PM	#1
stanger New Member 5 Rep 20 Posts Drives: 2009 335i Join Date: Jan 2011 Location: Washington State iTrader: (0)	Error code P0303, #3 engine misfire So I know that Cylinder #3 is misfire. I just recently replaced the plugs with the autolite iridiums, and the air cleaner. Ran awesome for few days, then it started to have a very rough idle at a stop. I tried to remove the plug, look at it and reinstall it, same issue, same cylinder. So I bought another plug, just to try and see if this fixed the problem, then I was going to check the coils by switching them, plugs were in store, Coils is special order. I first tried the spark plug and surprisingly it fixed the problem. So it must be a bad plug (New one), right? I mean, when a coil goes bad, can it send to much charge to the plug and ruin them? I know this may be a stupid question, but just wanted to ask before I purchase 6 coils, might as well do all if I do them. I have a long trip planne this Sat, so ...... Thanks for your replys
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04-11-2011, 11:00 AM	#2
Titanium3Series Second Lieutenant 14 Rep 255 Posts Drives: 2006 330i Join Date: Feb 2011 Location: Atlanta iTrader: (3)	Why would you purchase 6 coils when you only have a single misfire? what i would do is take the number 3 coil and move it to 4, 5 or 6 cyclinder or whichever one and see if the misfire will jump to the other cylinder once the car is running and a cycle being completed. IF the misfire jumps then most likley you have a bad coil. OR test the resistence of the coil if you can find the values
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10-13-2014, 12:01 PM	#5
le0.br4zuc4 New Member 3 Rep 14 Posts Drives: BLACK E90 Join Date: Feb 2014 Location: BOCA RATON iTrader: (0)	I have a 07 335i, 80k miles on it. I don't drive a lot, usually go to work on my bike. Thursday I got the P0303 code as well and car is misfiring. I will order the spark plugs and the coil as well. At 80K miles, should I replace the 1 coil or should I replace them all for peace of mind? Since I'm going to be working on replacing plugs and at least 1 coil, anything else I should replace while I'm working on that?
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04-11-2011, 11:05 AM	#3
fdriller9 Banned 252 Rep 7,089 Posts Drives: '06 AW 330xi Join Date: Mar 2009 Location: North Jersey/Philly/NYC iTrader: (4) Garage List 2006 330xi [6.44]	On an 06 I would probably replace all coils too.....just for peace of mind.
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