Most people know that oil lubricates moving parts. What they don’t realize is that it also cleans, dampens noise, acts as a coolant and helps in diagnosing engine problems.
Motor oil is to an engine what blood is to a human being. Clean oil picks up dirt, carbon deposits, metal particles and various other impurities from throughout your vehicle’s engine and like blood is passed through your kidneys for filtering, the oil is passed through the oil filter
where the majority of waste is trapped and left to do no harm. That is until the filter needs changing.
The rest of the impurities settle in the oil pan once the engine has been turned off and allowed to sit quietly for a while. If the oil is not changed regularly, though, some of the wastes will bond to the oil pan. This will in effect take them out of the flow but eventually they need to be cleaned off by a mechanic. The waste or crud that builds up on the oil pan can act as an insulator and make the engine run hotter than normal.
As mentioned before, some of the wastes in the oil are actually metal particles, usually from bearings, piston rings and other moving parts. Yes, even with the best lubricant you will still have some friction and with friction comes wear, from wear comes metal particles. To help remove this from your engine auto makers came up with a neat little trick of placing a magnet on the end of the oil pan, drain plug so that the pieces are attracted there and can be easily wiped off and discarded.
Quite simply, oil keeps moving parts from banging into each other which cuts down on some of the noise your engine makes. One way you know if you are running low on oil is if you hear that little annoying tapping sound from under the hood. Those are valves opening and closing but now, without oil, they are slamming shut and probably not opening as easily. It’s not a good practice to wait for this sound before changing your oil.
The oil in your vehicle normally should be changed every three months or 3000 – 4000 miles. Even with the expensive synthetic stuff you still need to stick with this same schedule.
Motor oil cools your engine in at least two ways. One, of course, by lowering friction between moving parts. Another way is by moving oil that has had a chance to sit in the oil pan and cool off, back through the engine which brings down the overall temperature.
Sometimes the oil is routed via a tube through your vehicles radiator where it is cooled much more efficiently than only being cooled in the oil pan.
One of the neatest uses of motor oil is as a diagnostic tool. I mentioned earlier that motor oil is like blood. This is so true. Let me first explain that the bearings and various other metal parts in your engine are made of a conglomerate of metals. Not just one. A single bearing may contain a mixture of aluminum, copper, mercury and even some precious metals. In some shops where very mission critical engines are used, the repairs can also be very costly. Mistakes are not a good thing in diagnosing problems in these situations. There are special “blood” tests so to speak. By taking a sample of an engine’s used oil and sending it to a special lab, it can be determined by spectrum analysis if the engine is wearing more than it should for its age. The lab looks at the amount and type of material deposited in the oil to pinpoint the problem.
All of the benefits of your motor oil are lost if you do not change your oil on a regular basis. You can check with your vehicle’s manufacture to see if they suggest a special schedule for changing oil but generally every three months or 3,500 miles, which ever comes first, is a safe bet. You wont regret it.