Infiniti Q Diesel Cold Start & Smoke: Glow Plug Alert

I had similar issues with my 2016 Infiniti QX70d last winter. The symptoms you're describing match exactly what I experienced rough cold starts, black smoke, and that annoying glow plug light staying on. Took it to my local Infiniti specialist last month when it had about 140k km. Turned out two glow plugs were completely worn out, and one was on its way. They checked the wiring harness too, which was actually fine. I got all four glow plugs replaced since they usually wear at similar rates. It wasn't a super serious issue, but definitely something you want to fix before winter hits. The repair was pretty straightforward took about 2-3 hours. My advice would be to get it checked soon, as faulty glow plugs can lead to starting problems and poor fuel economy. Make sure they check the control module while they're at it sometimes that can be the culprit rather than the plugs themselves.

Thanks for sharing your experience. That's really helpful to know since it sounds exactly like what I'm dealing with. Do you remember roughly how much you ended up paying for the whole job? Also, just curious has everything been running smoothly since the repair, or have you noticed any other issues pop up?

Hey again! Yeah, I can totally help with that. I actually just got mine fixed paid 560€ for replacing the faulty glow plug. The mechanic spotted it was worn out, just like they thought. And honestly, it was worth every penny because my QX70d's running like a dream now! The cold starts are perfect (which is such a relief with winter coming up), no more black smoke when I accelerate, and that annoying glow plug light finally stopped staying on. It's like having a different car, seriously. Haven't had a single issue since the repair, and it's been great on fuel too. If you're still looking for a mechanic, I can definitely say mine did a solid job. Sometimes these diesel issues seem scary, but once you get the right fix, they're totally sorted. Let me know if you need any other info!

Just wanted to update everyone I took my car to the mechanic yesterday based on the advice here. You were spot on! Got all four glow plugs replaced for about 600€, and wow, what a difference! The mechanic I found was super professional and explained everything clearly. No more black smoke, cold starts are smooth as butter now, and that annoying glow plug light is finally off. The whole job took about 3 hours, and they even gave my car a quick inspection while it was there. Turns out the timing was perfect because the old plugs were pretty much shot. Thanks again for the help, especially about what to expect. It really made me feel more confident walking into the shop. Definitely feels good to have this sorted before the weather gets colder. You all saved me from a lot of headache and probably some more expensive repairs down the line!