Overheating in Infiniti M: Water Pump Crisis?

Hey there! I had similar issues with my 2005 Infiniti Q45 last summer (I have some experience working on cars, but nothing too advanced). The symptoms you're describing sound exactly like what I went through. After taking it to my regular workshop, they found a faulty cable connected to the water pump control unit. The coolant was dropping because the pump wasn't working properly due to this electrical issue. Got it fixed for about 225 Euro (it was actually a pretty straightforward repair once they identified the problem). Since then, no more overheating or warning lights. What's your current mileage and have you noticed any coolant leaks under the car? This info would help me give you more specific advice. Also, are you getting any specific error codes? Might be worth checking those too. Btw, if it helps, my Infiniti had around 140k miles when this happened.

Thanks for sharing your experience! My mileage is at 29253 KM, and I just had it serviced last month. No visible coolant leaks under the car, but I'll definitely check those cables you mentioned. That's a relief it might just be an electrical issue rather than having to replace the whole pump. Haven't checked the error codes yet guess I should grab an OBD scanner . Did your coolant loss happen gradually or did you notice it dropping pretty quickly?

Hey again! Yeah, in my Q45, the coolant loss was pretty gradual at first I'd say I noticed it dropping over about 2-3 weeks before things got serious. But once the warning lights started popping up, it seemed to get worse pretty quickly. Since your mileage is way lower than mine was (mine was at 140k miles when it happened), I'm even more convinced it could be that electrical connection issue. These Infinitis are pretty solid, but those control unit connections can get finicky sometimes. Just to add to my previous reply after they fixed that cable issue on mine, I also had them do a pressure test on the cooling system just to be on the safe side. Might be worth asking your mechanic about that too. It's usually pretty cheap and gives you peace of mind that there aren't any slow leaks hiding somewhere. For what it's worth, my car's been running perfectly since that repair last summer no more overheating, no more warning lights, and the coolant level's stayed steady. Let me know what you find out with those error codes when you get them checked!

That's really helpful info, thanks! I'll definitely get that pressure test done along with checking the error codes. It's good to know your repair has held up well since last summer gives me hope this won't be too painful on my wallet! I noticed my coolant loss has been pretty gradual too, similar to what you experienced, so that's another sign pointing to the same issue. I'll swing by a workshop tomorrow to grab that scanner and check those electrical connections you mentioned. Really appreciate you taking the time to share your experience it's given me a much better idea of where to start looking. I'll update you once I figure out what's actually going on with mine!