JX35 Engine Problems: Stalling and Power Loss Mystery

Hey there! I had a somewhat similar experience with my 2015 Infiniti QX60 (pretty much the successor to your JX). I have some experience working on cars, but I mainly trust my regular workshop for bigger issues. Those symptoms sounded exactly like what I dealt with last year. In my case, it turned out that some vacuum hoses were cracked and needed replacement. Got it fixed at my trusted mechanic cost me around 175€ for new hoses and labor. Car's been running smoothly since then. But hey, could you share more details about your car? Like the mileage, when these issues started, and if you've noticed any specific patterns (like does it happen more when it's cold or hot)? That would help figure out if we're dealing with the same problem. BTW, have you scanned for error codes? That check engine light might give us some useful clues.

Thanks for sharing your experience! My JX has 37829 KM on the clock and I just had it serviced last month. The issues started about two weeks ago, and I've noticed it's particularly bad during cold starts in the morning. I haven't scanned for codes yet, but that's definitely next on my list. Really interesting about those vacuum hoses I'll have to look into that. Did yours make any specific sounds when the problem was happening?

Hey again! Yeah, actually when my QX60 had those vacuum hose issues, it made this kind of hissing sound, especially noticeable during cold starts pretty similar to what you're describing. Mine was around 45000 KM when it started acting up. You know what's funny? I initially thought it was the tank vent valve too (which is why I replied to your first post), but turned out those cracked vacuum hoses were the culprit. The symptoms can be really similar! I remember being super frustrated every morning because the car would shake like crazy until it warmed up. Since you mentioned yours is worse during cold starts too, it's sounding more and more like what I experienced. Definitely get those codes read when I did, I got P0171 and P0174 (lean condition codes), which helped point to the vacuum leak. Quick tip when my mechanic was diagnosing it, he used a smoke test to find the leaks. Maybe ask your mechanic about doing that? It made finding those tiny cracks in the hoses way easier. Trust me, it's worth checking the hoses before jumping to replacing more expensive parts like the tank vent valve. Let me know what those codes say when you get them read!

Thanks so much for all the detailed info! You're totally right I'll definitely get those codes read first before jumping to conclusions about the tank vent valve. The hissing sound you mentioned? I've been hearing something similar, now that I think about it. Funny how I didn't connect the dots earlier! I'll take it to my mechanic tomorrow and ask about the smoke test you mentioned. The fact that your issue was solved with just vacuum hose replacement gives me hope that this won't be a huge expensive repair. Will definitely update once I get the codes read and have my mechanic take a look at those hoses. Really appreciate you taking the time to share your experience it's helped point me in the right direction! You've saved me from potentially spending way more money than necessary on replacing parts that might not even be the problem. Thanks again!