Infiniti M Hybrid HVAC Issues: Common Valve Problem?

Hey there! I had some experience with a similar issue on my 2015 Infiniti Q70 Hybrid (I've also owned a Q50). I'd say I have some experience with cars, enough to understand the basics but not a pro. My symptoms were pretty much identical to yours heating/cooling issues and problems with the defrosters. Turned out it was a faulty cable connection to the water valve. Took it to my regular workshop, and they diagnosed it pretty quickly. The fix cost me about 155€ they had to replace some connections and the valve plug. Before I can share more specific details that might help you, could you let me know: Have you noticed any warning lights? Does it happen all the time or intermittently? Are you getting any weird noises from the heating system?

Thanks for jumping in! Mine's at 6299 KM since my latest service. Actually, I'm getting an intermittent whirring sound when the heating's running, but no warning lights so far. The issue started about two weeks ago it's not constant, but definitely more noticeable in the mornings. Your experience with the faulty cable connection sounds pretty similar to what I'm dealing with. Did your mechanic mention any other potential issues to look out for?

Hey again! Yeah, I totally remember when this happened to my Q70 Hybrid. Actually, when you mention that whirring sound, it's giving me flashbacks! I had that exact same noise it's pretty distinctive, right? Like a weird whirring that seems to come and go? When my mechanic was working on it, he did mention a couple other things to watch out for. The cable connection was definitely the main culprit in my case, but he said these systems can also have issues with the actuator motor and the blend door. He recommended keeping an eye on the temperature gauge and watching for any inconsistent temperature changes. Since you mentioned it's more noticeable in the mornings, that's exactly how mine started too. The 6299 KM since your last service isn't too high, but these hybrids can be a bit finicky with their cooling systems. My mechanic actually advised me to get the entire HVAC system checked during each service after that incident, just to be on the safe side. Quick question when you're having the issue, have you noticed if adjusting the temperature settings makes any difference at all? In my case, there was almost no change in temperature no matter what setting I used, which was a pretty clear sign something was up with the valve control. BTW, that €155 fix I mentioned earlier turned out to be totally worth it haven't had any issues since then.

Thanks for all that detailed info! That's super helpful, especially about the actuator motor and blend door definitely going to mention those to my mechanic. And yes, you nailed it about the temperature settings! I've been playing around with them, and just like your case, there's barely any change no matter what I do. The whirring sound is exactly as you described it's like a weird electronic hum that comes and goes. I'm actually feeling a lot more confident about getting this fixed now. €155 sounds pretty reasonable compared to what I was worried it might cost. I'll definitely take your mechanic's advice about regular HVAC checks too seems like a smart way to prevent future headaches. Thanks again for sharing your experience you've really helped me narrow down what's probably going on with my car!