QX Diesel Tank Flap Issue: Fix for Check Engine Warning

Hey there! I've got some experience with cars (low experience), and I actually faced something similar with my 2016 Infiniti Q50 diesel. The tank flap issue was driving me crazy too! Turned out it was a faulty linkage mechanism in the fuel door system. Took it to my trusted workshop last summer, and they had to replace the entire actuator unit. Cost me around 210€, but it fixed the problem completely. Before you head to the shop though, could you share what model year QX you have and if you're noticing any other symptoms? Like, does the fuel door feel stiff when trying to open it manually? This info would help me tell if it's the same issue I had. Hope this helps!

Thanks for sharing your experience! My QX has 129,349 KM on the clock and was just serviced last month. Yeah, I've noticed the fuel door feels a bit sticky, especially during cold mornings. Sometimes it takes a couple of tries to get it open, even using manual release. Sounds pretty similar to what you described. Guess I should brace myself for that actuator replacement bill! Really appreciate the heads up on the potential cost – at least now I know what I might be looking at.

Hey again! Thanks for those extra details about your QX. Yeah, that sticky fuel door behavior, especially in cold weather, is exactly what I dealt with on my Q50! It's like déjà vu hearing you describe it. I meant to mention earlier before I got mine fixed, I tried cleaning around the mechanism with some WD-40 (being super careful not to get any near the paint or rubber seals). It helped temporarily but the problem kept coming back, which is what finally pushed me to get the actuator replaced. With your mileage being pretty close to what mine was when it acted up (I was around 125,000 KM), it's definitely pointing toward the same issue. Just to add to my previous reply the repair took about 2 hours at my shop, and they actually found some corrosion on the old actuator when they removed it. Apparently, it's a fairly common wear item on these Infinitis. Let me know how it goes when you get it checked out! Always curious to hear if other owners' experiences match up with mine.

Thanks so much for all the detailed info and the WD-40 tip! It's really reassuring to hear from someone who's been through the exact same thing. I'll definitely skip the temporary fixes and just go straight for the actuator replacement – seems like that's the real solution here. I've actually booked an appointment at my local Infiniti dealer for next Tuesday, so I'll let you know how it turns out. Really appreciate you taking the time to share your experience in such detail. Your insights have definitely helped me avoid the trial-and-error phase and go straight to the actual fix. Thanks again for all your help!