The fan in my 850 BQ might be going out. I hear a clicking coming from it and the clicking stops when I jam the fan.
Are there alternate fan replacements available or is there a simple fix like lowering the fan curve?
Not even sure if I can do the latter.

Try pushing the fan down a few times to reseat the bearing.

One thing to keep in mind is the fans inside a PSU are not replaceable by the end user and even unplugged a PSU can still hold enough charge to give a serious injury or death. If you can't get the fan bearing to reseat itself then it's best to contact EVGA for a replacement. Do not open a PSU unless your an electrician certified in PSU repair.
 
I know it should go without saying but sometimes people think that an off the shelf fan will fix an issue in a few minutes but it really isn't that simple.

You can replace the fan if it comes down to it and you're willing to take the risk of opening up a PSU..I have done it a handful of times, no real biggie..You need to cut the connectors off of the ends (because they're different) and wire the positive to positive and negative to negative.
 
But as stated above, the PSU has residual voltage that can kill or injure.
 
What's in it now is a Globe Fan RL4Z T1352512HH, 140mm, 12V, 0.45A, 1200rpm, 129.76 CFM, 38.8 dB, Teflon Nano Bearing fan..You can just use an equivalent/approximate 140mm case fan.
 
 
That PSU should have a 5 year warranty, so you can RMA it if it's still covered.

bob16314
You can replace the fan if it comes down to it and you're willing to take the risk of opening up a PSU..I have done it a handful of times, no real biggie..You need to cut the connectors off of the ends (because they're different) and wire the positive to positive and negative to negative.
 
But as stated above, the PSU has residual voltage that can kill or injure.
 
What's in it now is a Globe Fan RL4Z T1352512HH, 140mm, 12V, 0.45A, 1200rpm, 129.76 CFM, 38.8 dB, Teflon Nano Bearing fan..You can just use an equivalent/approximate 140mm case fan.
 
 
That PSU should have a 5 year warranty, so you can RMA it if it's still covered.

Very good advice. If you are not any type of expert or qualified technician for power supplies don't take any risks and RMA your PSU if under warranty. 

 
When it comes to PSU's, I say leave those things to the pros. Don't open.