Chosen Solution
Left fan makes noise
Most likely your system is very dusty and needs a good cleaning. Get a small soft paint brush and a can of can’ed air. Pop off the bottom cover and then carefully dust out the fans and logic board. Use the can’ed air to blow the mess out of the system. Don’t blow to hard or long on the fan blades. I would recommend you get a good monitoring app like TG Pro it will allow you to see the health of the fans and review the thermal sensors within your system for issues. If after cleaning the fan is still running ruff, you’ll need to replace it. Sadly, you didn’t tell us what your model is so we can’t give you the rest of the info …
