Hot Q50 Diesel: Aux Pump Problems & Solutions?

Hey there! I had something similar with my 2017 Infiniti QX (also diesel). I've got some experience working on cars, but I usually leave the complex stuff to professionals. Had the same symptoms engine running hot and warning light. Took it to my trusted workshop and turned out it was just a faulty cable connection to the auxiliary pump. They fixed it for about 170€ mostly labor costs since they had to access some tight spots to replace the connection. Quick question what's your mileage and have you noticed any coolant leaks? This could help narrow down if you're dealing with the same issue I had. Feel free to share more details about your Q, and I'll try to help further!

Thanks for sharing your experience! My mileage is at 238770 KM, and I just had the regular service done last month. Haven't noticed any coolant leaks yet, but I'll definitely check that out. The temperature issue started just a couple days ago. Did your car also have any weird noises before the problem showed up? Mine's been making a slight whirring sound from the front end.

Hey again! Thanks for the additional info. Yeah, my QX actually did make a similar whirring noise before things got worse it's quite typical for these Infinitis when the pump starts acting up. My car had about 210,000 KM when this happened. That whirring sound you're describing sounds very familiar mine was coming from the front right side of the engine bay. Looking back, I probably should've gotten it checked as soon as I heard it, but you know how it goes... we always hope it'll just go away! Since you've just had your service done, did they mention anything about the coolant system? The timing of this is interesting because sometimes these issues can pop up right after a service if something wasn't reconnected properly. In my case, the mechanics found that the connector had some corrosion too, which contributed to the poor connection. One quick tip while you're waiting to get it checked out, keep an eye on your temperature gauge during your drives, especially in traffic. If you notice it climbing quickly, better pull over and let it cool down. Not worth risking engine damage! Let me know what you find out when you get it checked. Really curious if it's the same issue I had!

Thanks so much for the detailed response! The whirring noise is exactly where you described front right of the engine bay. And no, the service guys didn't mention anything about the coolant system last month, but I'll definitely bring that up when I take it in. Really appreciate the tip about watching the temperature gauge I've been a bit paranoid about it already and have been keeping a close eye on it during my commute. I'll make an appointment with my mechanic tomorrow morning and get this checked out before it potentially becomes a bigger issue. The fact that your problem was just a faulty connection gives me hope that it won't be too serious (or expensive!). I'll update you once I know what's going on. Thanks again for sharing your experience it's been super helpful!