So normally when I start the Pathfinder up when the engine is cold there is a noticeable roar which sounds like fans starting up. It happens for 1-2 seconds at the start and then the sound level drops down to what you would expect at idle. This sound is most obvious when the engine is cold. If it's warm, you won't hear as much of a roar. It's been this way for the past three years.
However, recently I've noticed that during a cold start, the roar I would normally hear isn't happening. Everything seems to be running fine, but the sound on start up is definitely different and sounds as if something doesn't have enough power. Anyone know what I'm referring to? Is the sound I'm hearing a fan blade revving up?