Yes balanced is the "norm". I still say either the fan is starting to die or a sensor on the fan.
If you wish to fix it yourself, it is not incredibly hard actually.. I'm all for encouraging people to get to know their devices.
If you are even slightly mechanically inclined.. replacing the fan is not actually hard. That being said of course neither myself or Windows Forums is responsible if you break your device
A good rule of thumb is to find 2-3 videos on YouTube for taking apart your model and watch them BEFORE performing the surgery. When removing the screws from the bottom of your laptop usually you'll need to slightly pry the case apart to get the bottom off. It's always good to use a PLASTIC tool for this, not METAL (as metal will scuff up the plastic and possibly break it in the process).
I strongly advise replacing any thermal paste while your in there, which means you have to take off the heat-pipe that distributes the heat over to the fan.
When this is taken off there is an order to which the screws should be loosened and tightened (they are even numbered for you), and they should never be over or under tightened. If you are worried about how tight they should be, start by unscrewing them slightly then back tight so you get an idea how they came originally. Most people just refer the tightness needed as "hand-tight" but if you are inexperienced you may be a bit nervous and that's OK. See below image I found about your model. The fan comes out easily with a few screws, the heat-pipe is the black pipe that runs over to your CPU.
You'd need to clean the CPU's die off of any existing thermal compound. I usually wipe it dry with a paper towel, then after the bulk of it comes off use a cotton ball with alcohol on it to clean the surface. You'll also want to clean the underside of the heat-sink where the thermal compound touched it.
A good thermal compound for this particular use is Cooler Master Master Gel, you don't need much just about the size of a medium sized sweet pea. It's not cheap, but you can buy the smallest syringe of it as you really do not need much at all.
Now all of this being said... I'm not sure EXACTLY which Dell 5570 model you have, usually there is a sub model like 15-5570, or something similar. I believe I've found the fan on Amazon for $20.. but I'm hesitant to link you to the incorrect part without making sure 100% it fits your model. If you private message me your machine's Service Tag (or serial number) I can look it up on the Dell site and make sure.