I’m wondering if anyone can give me some insight as to what this noise may be
The car runs and drives fine but over the past few days I’ve started hearing a faint supercharger-like whine coming from my engine bay. It starts happening at about 2K rpms and increases in pitch until about 4K rpms. After that the exhaust is too loud and the pitch probably too high for me to hear. It happens in any gear on my 7AT, with the AC on or off, and regardless of engine temp.

I’m hoping it is something accessory belt related, but I have seen a few posts on Nissan Frontier forums showcasing a similar sound that ended up being related to the timing chain tensioner guides. Has anyone else encountered chain guide issues, and if so what mileage did you need to service them at?

 

The whine in this video is much louder, but similar to what I’m hearing.

 

so it turned out to be my battery.

 

Umm... Batteries don't whine. 🤔
Maybe the alternator was generating excess voltage to compensate for a bad battery, but the battery itself does not produce noise.

 

Exactly. I should’ve been more clear in what I meant by “battery”