[bloppitybloop]

I have a 2007 e90 335i. My only mod is a JB4.

Anyway, I was traveling on the interstate on Friday and was passing a slow moving semi. I pushed down on the gas and a few seconds later my Service Engine Soon light came on and the car started running a little rough.

After about a minute, the problem went away. Later on Friday, I accelerated quickly from a stop sign up to about 45 or 50 and the same thing occurred and went away.

I checked for a code on the JB4 but there was nothing.

Does anyone know what the problem could be?

Thanks in advance.

[ThatRWD]

Same, likely a misfire due to bad spark plug(s) or your coil pack(s). Mine does it on cold starts, just replaced plugs we'll see how it goes. Plugs should be changed ~45k per BMW, ~16K per tunes from what i have heard.

[bloppitybloop]

Originally Posted by ThatRWD

Same, likely a misfire due to bad spark plug(s) or your coil pack(s). Mine does it on cold starts, just replaced plugs we'll see how it goes. Plugs should be changed ~45k per BMW, ~16K per tunes from what i have heard.

I have about 33k miles on my car. I guess I'll try changing the spark plugs and see if that helps.

[Jeff@TopGearSolutions]

Likely spark plugs with that much mileage on stock ones. 20-25K on a tuned vehicle is common practice for spark plugs.

[iturbo_bmw]

misfire probably due to spark plugs


look at the misfire sticky

[bloppitybloop]

Originally Posted by iturbo_bmw

misfire probably due to spark plugs


look at the misfire sticky

Thanks.

I actually read that shortly after my first post in this thread. I should've been more patient and looked around just a bit more.

[ThatRWD]

I had 32k when i had my first misfire though it did sometimes rumble the car a bit without any misfire codes or lights. Currently at 33k. But never happened during a warm day only cold days. Also doesn't always happen right away, i gotta start it up start driving and then 2-10 minutes later misfire. But if i push it and keep going, letting it warm up the misfire stops.

Swapped my plugs yesterday, there was some gunk in cylinder 3 which is where the misfire was happening. But the oil was on plug 4. Towards the top. Did swap coil 3 with coil 4 before putting in the new plugs.