BMW Z3 Starting Issues: Bad Sensor or Something Worse?

Hey there! I had similar issues with my 2005 BMW Z4 last year. The symptoms you're describing match exactly what I experienced, rough starts, misfiring, and power loss. In my case, it turned out the camshaft position sensor was indeed faulty, and there was also a loose connection in the wiring harness. The repair wasn't majorly complicated, took about two hours at the garage. The mechanic showed me the old sensor, and you could see clear signs of wear. Once replaced and the wiring fixed, the car ran like new again. The check engine light disappeared immediately after the repair. It's definitely worth getting it checked out soon, these symptoms can lead to bigger problems if left unattended. In my case, I was lucky I caught it early. While the camshaft sensor is often the culprit with these symptoms in BMWs, have a professional diagnose it to be sure. Just my two cents based on my experience.

Hey, thanks for sharing your experience with the Z4! Your situation sounds exactly like what I'm dealing with right now. Just curious, do you remember roughly how much you ended up paying for the sensor replacement and wiring fix? Also, has everything been running smoothly since then, or have you noticed any other issues pop up? I'm trying to figure out if I should expect any related problems down the line.

Hey again! Happy to update you! Yeah, after taking it to my mechanic, it turned out to be exactly what I suspected, a faulty camshaft sensor along with a bad cable connection. The total bill came to 95€, which was actually less than I expected. They just had to fix the plug connection that was causing the trouble. Since getting it fixed, my Z4 has been running absolutely perfect. No more rough starts, no misfires, and the power's back to normal. The check engine light hasn't come back either. It's been such a relief, honestly. I've put quite a few miles on it since then without any related issues popping up. Best decision I made was getting it sorted quickly. These BMWs are pretty solid once you address these kinds of issues promptly. If your symptoms are matching what I had, I'd definitely recommend getting it checked out. Small problems can turn into bigger headaches if you wait too long, you know? Trust me, once you get it fixed, you'll notice the difference right away. The car just feels right again.

Thanks so much for the detailed follow-up! Actually, I bit the bullet and took my Z3 to a mechanic yesterday. You were spot on, it was indeed the camshaft sensor causing all the trouble. The mechanic found some worn-out wiring too, just like in your case. The whole thing cost me a bit more than yours, but honestly, I'm just happy it's sorted now. The car feels completely different, starts up smoothly, runs great, and that annoying check engine light is finally gone! Funny how I was so worried about going to the mechanic after my last bad experience, but this time it worked out perfectly. The guy even showed me the old sensor and explained everything clearly. Should've done this weeks ago instead of stressing about it. Really appreciate your help, it gave me the confidence to get it checked out. Now I can actually enjoy driving my Z3 again without wondering if something's about to go wrong!

Hi I have a 2005 e46 330d it's having starting issues once running it's fine bit will kill the battery trying to start I have replaced egr,glow plugs and modual and crank shafts breather for a vortex one and put a more powerful battery on the car was running loverly and had just completed a 700 mile round trip when I had a abs light come on I plugged a cheap obd reader in and cleared faults only to be left with a starting issue any advice would be great full. Regards Andy

Start by checking the battery connections and ensure they are clean and tight. A weak or poor connection can cause starting issues. If the connections are fine, consider testing the battery voltage and alternator output to ensure they are functioning correctly. A failing alternator might not charge the battery properly, leading to starting problems. Let me know how it goes or if you have any further questions!