Car is an ‘06 325i. I should start by saying I had this issue about 2500 miles ago and it was originally resolved by changing the plugs. But now it’s back and I can’t track it down yet. Symptoms: After driving the car for about 5-10 minutes, the car will intermittently stumble while idling. To be specific, it’s like the idle suddenly (and strongly) drops/engine shudders and then it idles smooth for a few more seconds. Then it will stumble again, anywhere from a few seconds to almost a minute in between stumbles. Once you start driving, there are no issues; the car accelerates smoothly and drives normally. But if you come to a stop for more than 10 seconds or so, it will start stumbling again.

INPA shows no codes. To be sure I also hooked up another scan tool (Torque) and no codes there either. I have only replaced my coils in the past when they have failed and thrown codes. As of now at least 4 of them are less than 2 years old. The plugs are 2500 miles old. Long term fuel trims are between 5 and 7 percent negative, but short term trims hover normally between -1.7 and +1.7. I would have thought that a failing coil would register misfires but again I’m not seeing any logged. Valve cover gasket is also pretty new and I don’t have any oil seeping into the plug chambers…

Any suggestions? Thanks!