I changed my oil this past weekend with 15w-50 Mobile1, thats what the car parts store said to use, even though i knew better and i shouldve used 0w or 5w since its getting cold out

but today i get out of my car after taking it for a 20 min spin and i hear a small knocking or tapping sound, i pop the hood and it sounds like its around the fan.

this just started today im pretty sure

if the knocking is being caused by the new oil viscosity, will i need to change the oil immediately and will any damage be done by this knocking sound or will i be fine to just live with it until the next oil change?

any help is greatly appreciated

IF the knocking is from the lifters etc, additional wear/tear on the engine internals is being caused. I wouldn't call that "damage" but premature wear.

But if it's from the fan then that doesnt matter lol.

I changed my oil this past weekend with 15w-50 Mobile1, thats what the car parts store said to use, even though i knew better and i shouldve used 0w or 5w since its getting cold out

but today i get out of my car after taking it for a 20 min spin and i hear a small knocking or tapping sound, i pop the hood and it sounds like its around the fan.

this just started today im pretty sure

if the knocking is being caused by the new oil viscosity, will i need to change the oil immediately and will any damage be done by this knocking sound or will i be fine to just live with it until the next oil change?

any help is greatly appreciated
It's not the oil. I always use Mobil 1 15/50 and in fact was ab out to change my oil tonight.

Yeah, I doubt it's the oil. In a really dirty engine M-1 can break sludge loose but I don't think you are in that situation. Too thick an oil may bother your cranking and make the car harder to start when way cold, but I don't think the 15-50 M-1 will give you trouble there in Md. Minnesota, Idaho, Alaska, yeah, it might not work there. But I think you will be OK.

Feel of the fan with the car off, is the bearing loose? If you have the right tool you can take the fan off and see if that makes the noise go away.