The Ultimate Comparison Hot vs. Cold Engine Oil Checks

Run your engine up to operating temperature. Make sure that you are on level ground. Turn your engine off and wait 5 minutes and check your oil ... Imagine a dipstick going into a pan of oil that has accumulated over night...straight in...how is it going to be inaccurate? Make sure your vehicle is parked on level ground, turned off, and that the engine is cold. Open up the hood of the car and find the dipstick. Remove the ... As far as when to check it, best to check when warm and after the engine has been shut down. Depends how the dip stick was designed to be ... Some say to check oil when cold (overnight) while others say to check 5 minutes after shut down. Some say that hot reading is higher up on dipstick than cold ... cold. if you check it warm, some of the oil will not be in the sump, so it will read low. also, too many people depend on ... Do you then wait until the engine is cold before topping it up. Also the engine will expand as well as the oil when its hot making the sump ... Checking with the engine cold will allow all the oil to drain back down to the oil pan thus providing a slightly more accurate reading. Only add oil IF the level is at the low mark -no sooner or later than that. You will really screw things up overfilling the engine. The best time to check the oil in the engine is when the engine is cold or sitting there overnight. That is what I do. I still have my doubts though.