If your furnace starts acting weird, there are a few oil furnace troubleshooting tips that you can try. Remember, if there is any type of smoke, fire, or even a burning smell, call your local fire department just o be safe. Other that that for things such as rattles, clanks etcetera, you can do some minor checks that may help you find the problem. First if you are hearing a rattle, make sure your filter is installed properly, if it is lose it can cause a rattle, especially a metal filter. Also check if the cover is on snug. Using a few deduction skills you can find the culprit quickly and safely.