I know some fan motors have ports to oil but many do not (bathroom exhaust fan, bathroom heater fan, regular house fan, etc). How do you oil the ones that do not have ports?

Specifically, where do you put the oil 3-in-1 oil?

Edit: The model I'm maintaining is NuTone 765HL (https://www.broan-nutone.com/en-us/product/ventilationfans/765hl) ad it says the heater fan is sealed but doesn't mention anything about the vent fan.

  • 2
    If the motor has sealed bearings it may not need oil at all.
    – Tyson
    Dec 17, 2018 at 1:14
  • 1
    Why are you assuming that 3-in-1 oil would even be suitable for the task?
    – jsotola
    Dec 17, 2018 at 2:34
  • At least he's not using WD-40! Dec 17, 2018 at 22:32

2 Answers 2


You'll need to check the manual to be sure but if you don't see ports, chances are they are sealed like Tyson said and don't need maintenance by you. And for motors that do need oiling, manual should tell you what kind of oil you need.


Most of the fans have oil lite bearings that if there are no ports the motor can be opened and the fibers that hold the oil can be saturated with motor oil.

  • 1
    Dang. So if it's sealed but still kind of noisy what do you do? Just replace it? Dec 17, 2018 at 15:02
  • 1
    Most of them can be dissambled if it can't I would looked at the ends of the motor sometimes there are mall holes that you can add drops of oil at the holes, some are on the side at each end just a small opening many times not even marked, a drop of oil on the shaft can even help for a while.
    – Ed Beal
    Dec 17, 2018 at 15:38

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