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moojin_gw

SAE 10 Non-Detergent Oil

moojin
17 years ago

I've isolated an issue with my furnace to the Combustion Gas Exhaust Blower Motor and that it needs some oil. I've read that I should put a few drops of non-detergent SAE 10 (or 20, which is better?) oil into the oil port. I've located the oil port (which looks like a small plastic tube).

Where do I buy SAE 10 non-detergent oil? I've looked at some websites for auto-parts stores, but they seem to only carry SAE 10W-30/40 which I believe has detergents in it. Perhaps, I'm incorrect. What is the sizes of container it comes in? Is there a type of applicator that would easily allow me to feed the oil into the oil port?

If you are curious, the issue with the Combustion Gas Exhaust Blower Motor is that it sounds like a helicopter starting up once the thermostat turns on the furnace. The sound subsides after about 20 seconds and only occurs when the furnace is started after a period of time of not being used (2 or 3 hours). I've read several posts on this website and several other websites that seem to indicate that the motor needs oil.

Thanks for your help.

Andrew

Comments (9)

  • bob_brown
    17 years ago

    3-1 motor oil is one brand. Many other oils in a small 2-4 oz containers. Use non detergent. Penetrating oil is not the same thing?

  • jbac
    17 years ago

    we use a zoom spout available at most hvac supply stores around here such as johnstone.think it is turbine oil.

  • kalining
    17 years ago

    If your motor has bearing slap from lack of oil it's too
    late. All the oil will do it take up space closing the
    tolerance of the shaft and bearings until it needs more oil. Replace the motor.

  • davefr
    17 years ago

    Regular 3 in 1 oil is 10 weight non detergent. They also make a 3 in 1 for electric motors and I believe it's 20 weight.

    My favorite oil for motors is Royal Purple Syn Film ISO 68.

  • moojin
    Original Author
    17 years ago

    kalining - What is bearing slap? I tried to look it up on the Internet, but couldn't find a description of what it would sound like. I'm thinking that it would sound like knocking sound, such as if I threw a few bolts in my dryer and turned it on. If that is the sound, luckily I'm not at that point yet. The sound that the combustion gas inducer motor sounds like is: "Wraaaaah, wraaaah, wraaah, wrah, wrah, wrah, wrah." Then it transitions it a regular sound.

    Andrew

  • kalining
    17 years ago

    That is pretty close. It is when you can move the shaft
    back and forth as in side to side inside the bearing, actually the bushing. Ever heard the squeal and bad viberation in a bad heater motor of a car ? Same thing.

  • blacknumber1
    17 years ago

    Induced draft motors all seem to use cheap sleeve bearings, I have yet to see one that the motor actually was burned out, all the ones I come across have bearings locked up. How hard would it to be to make a IDM that has real sealed ball bearings that will actually last 20 years?

  • moojin
    Original Author
    17 years ago

    I did some more research and found a schematic for my motor here: http://www.aosmithmotors.com/

    On the WD40 website, they have a FAQ about "3 in 1 oil" and it verifies that it is SAE 20 and non-detergent.

    http://www.wd40.com/Brands/3in1_faqs.html

    I think it would be better if they wrote that on the bottle, since I had it in my hand last night at Home Depot last night.

    Thanks for all of your insights. I will be picking up a bottle tonight.

    Andrew

  • bus_driver
    17 years ago

    The noise you describe does sound like worn sleeve bearings. Oiling probably will help for while, perhaps a long while. Nothing to be lost by trying. If replacement does prove to be necessary, oiling the old one will not make it more difficult nor more expensive.