BMW 4-Series Ignition Coil Issues: Symptoms & Solutions

Hey there! I have some experience with cars and had a very similar issue with my 2013 BMW 3-series (also owned a 5-series before). The symptoms you're describing sound exactly like what I dealt with. My car was doing the same, rough idle, jerking, and that annoying check engine light. Turned out to be a loose connection in the ignition coil wiring harness. The workshop found a damaged cable that wasn't properly connected to the coil. Got it fixed for about 95 Euro, they replaced the damaged wiring and checked all connections. Car's been running smooth since then. The diagnosis was pretty straightforward with their diagnostic tool. Could you share which engine variant you have in your 4-series? Also, did you scan for error codes? This would help me give you more specific advice based on my experience. Pro tip: Don't wait too long to get it checked, driving with faulty ignition components can cause more expensive problems down the line.

Thanks for sharing your experience! My car has the same symptoms, and it's good to know it might just be a wiring issue. I've got the 2.0L gasoline engine with 113308 KM on the clock. Haven't scanned for error codes yet, but will definitely do that before heading to the workshop. I was worried it might be something more serious, but your repair cost gives me hope it won't break the bank. Just had my service done last month, and everything was fine then, so this came as a surprise. Will get it checked ASAP to avoid any further damage. Thanks for the heads up about potential complications if left unchecked! Did your car give any warning signs before these issues started, or did it just happen suddenly?

Hey again! Thanks for providing those details about your 2.0L engine. Actually, in my case, it started quite subtly, I first noticed minor hesitation during acceleration about a week before the more serious symptoms kicked in. I initially brushed it off (big mistake), thinking it was just bad fuel or something. Looking at your mileage (113308 KM), it's pretty close to what mine was when I had the issue (around 110000 KM). The fact that it started right after your service is interesting, sometimes these problems can pop up when components are disturbed during routine maintenance. Just to add to my previous response, after fixing the wiring issue, my mechanic actually recommended checking all the ignition coils as preventive maintenance. They tend to wear out around this mileage on these BMW engines. I ended up replacing two coils that were showing early signs of wear, even though they hadn't failed yet. Bit pricey but worth it for peace of mind. One thing I forgot to mention earlier, while my main issue was the wiring harness, when these symptoms show up, it's worth checking the spark plugs too. They're often related and can cause similar symptoms. When was the last time you had yours changed?

Thanks for that additional insight! No kidding about the subtle start, mine actually began with slight stuttering during cold starts about two weeks ago, but I also ignored it thinking it would go away. Really regretting that now! You're probably onto something about the service connection, they did have to access that area during the maintenance. As for the spark plugs, they were changed about 30000 KM ago, so they should still be okay, but I'll have them checked anyway while they're looking at the coils. I really appreciate you sharing about the preventive coil replacement. I'll definitely discuss that with my mechanic, rather spend the money now than risk getting stranded somewhere. You've been super helpful with all this info. I've got my workshop appointment booked for tomorrow morning, so fingers crossed it's just the wiring harness like yours was!