Running your car on low engine oil levels is never a good idea. Most of us know that engine oil is needed to cool down the moving parts, but it does a lot more than that! Besides cooling, engine oil provides cleaning, lubrication and a bunch of other chores. And when your oil levels are extremely low for prolonged periods of time, catastrophe will strike without a doubt, as with this poor Mercedes C120.
In case you have been moving around on low oil levels, the small amount of oil being pushed around the engine block will get hotter and hotter. This is because the liquid is not given enough time to cool down before going back into circulation, which means oil will break down really fast.
Fully synthetic oils will last longer than refined oil, but they too will break down sooner or later. Due to heightened temperatures, the oil will undergo several reactions such as oxidation, thermal degradation, and compressive heating. All these processes happen to oil anyway, but they will be accelerated due to the extreme conditions, lowering the life of the oil.
All this breakdown will create the very things oil is supposed to remove, tar; sludge; varnish; soot;, etc. All of these carbon deposits will start to build up on the internals of your engine, e.g. the rings, bearings, cylinder walls, essentially anywhere the oil flows. As these carbon deposits build up, anything that comes in contact with them gets sticky and hard, reinforced by the high temperatures. This begins the catastrophic process of friction between the parts, which means the lack of oil is now creating more heat, more deposits and actually contributing towards producing friction.
The metallic surfaces inside the engine will now become susceptible to the increased wear, with the oil breaking down and the temperature inside the engine continuing to increase. Most of the times some part of your engine finally gives in, usually the first thing being the rod or main bearing.
Throwing a rod means that the friction on the bearing at the rod journal of the crankshaft gets too high, which thus overcomes the strength of the rod and results in its catastrophic plastic deformation. In this event, the piston inside the bore goes down and fails to return since the rod is no longer attached. It can even slip down to the oil pan and flung around inside it, while the rod itself will break and force itself out the side of the engine block.
There’s no coming back from here, and you’ll definitely need to replace your engine!
Watch this video below to see how running your engines on low oil levels even for a small period results in massive wear.