Z4 Fuel Pump Failure: Starting & Stalling Nightmare

Hey there! I've got a 2018 BMW M240i and had almost identical symptoms last month. The rough idle, hard starts, and fuel consumption issues you're describing are exactly what I experienced. Initially thought it was the fuel pump too, but when I finally got it checked, turned out to be corroded wiring connectors at the fuel pump assembly. The connection was loose and intermittent, causing all those symptoms. Had it fixed at an independent BMW specialist. They cleaned the connections, replaced the damaged wiring harness section, and double-checked the fuel pressure. Not a super serious repair, but definitely something you want to address soon before it leaves you stranded. My advice? Get it checked by a reputable BMW specialist. While fuel pumps can fail, often it's the electrical connections that cause these symptoms. Better to know for sure than guess. Don't wait too long though, running rough can damage other components if left unchecked. Hope this helps with your decision!

Thanks so much for sharing your experience! This is super helpful as I've been worried sick about potential repair costs. That's really interesting about the wiring connectors, definitely gives me something specific to mention when I take it in. Just wondering, do you remember roughly how much you ended up paying for the whole repair? And has everything been running smoothly since they fixed it? Would love to know if any other issues popped up afterward.

Hey again! Happy to give you an update! Yeah, took it to the specialist last week and you'll be glad to know it was exactly what I suspected, just the wiring connection to the fuel pump giving trouble. The repair was pretty straightforward and cost me 95€, which was a huge relief considering I was worried about needing a whole new fuel pump! The car's running like a dream now, no more rough starts, stalling, or that annoying rough idle. Fuel consumption is back to normal too. It's amazing how such a small electrical issue can cause so many symptoms and headaches! Haven't had any other problems pop up since the fix. The mechanic did a thorough check while they were at it, and everything else looked good. Just goes to show it's worth getting these things checked out by someone who knows what they're doing. Really happy I could help point you in the right direction with this. These BMWs can be tricky sometimes, but once you sort out the little gremlins, they're fantastic cars!

Thanks for the follow-up! Finally got my Z4 checked out yesterday and you won't believe it, my issue was different than yours but still not as bad as I feared. Turned out to be a clogged fuel filter and some dirty injectors. The mechanic I found was great, really took the time to explain everything. Total bill came to about double what you paid, but still way less than a new fuel pump would've cost. They did a complete fuel system cleaning and replaced the filter. Car's running amazing now, starts right up and idles perfectly. No more check engine light either! Really appreciate you sharing your experience, it gave me the push I needed to get it looked at instead of just worrying about it. Sometimes these car problems seem huge until you actually get them sorted. Guess we both got lucky with relatively simple fixes! Anyway, time to enjoy my smooth-running Z4 again. Thanks for all your help with this!