What can be added to engine oil that is highly harmful to the engine?
3 Answers
Adding sugar to engine oil is highly harmful to the engine. The functions of engine oil are: lubrication, auxiliary cooling, cleaning, sealing and leak prevention, rust and corrosion prevention, shock absorption, and anti-wear. The maintenance methods for the engine are: 1. Use qualified engine oil; 2. Use qualified coolant and antifreeze; 3. Regularly clean the scale in the radiator; 4. Regularly clean engine carbon deposits; 5. Regularly replace the three filters in the car; 6. Maintain a reasonable engine speed. The components of the engine include: the engine block, the crankshaft and connecting rod mechanism, the valve train and intake-exhaust system, the fuel supply system and governor, the starting device, the cooling system, and the lubrication system.
Having worked in the auto shop for so many years, I've seen plenty of cases where adding the wrong substance to engine oil ruined the engine. Adding water is the dumbest—once water gets into the oil, it emulsifies, forming a milky foam that completely destroys lubrication, causing instant wear on pistons and bearings, and in severe cases, cylinder scoring. Then there's adding coolant—the antifreeze components corrode metal parts like the crankshaft and connecting rod bearings. Don’t think adding gasoline or diesel will clean anything either; it instantly thins the oil viscosity, leading to increased bearing clearance and total engine failure. The worst is randomly using additives, like those cleaning agents bought off Taobao, which chemically imbalance and dissolve the oil film, causing dry friction on cylinder walls. Remember, engine oil is a precisely formulated blend—adding anything non-original is asking for trouble, and repairs start at thousands of yuan when things go wrong.
I have an old Jetta, and when I was young and reckless, I added all sorts of things to it without knowing better—now I’ve learned my lesson. Once, I added a bit of water, which caused the oil to emulsify and thicken, leading to loud engine noise, rapid oil pressure drop, and accelerated wear. Another time, I mixed the wrong oil—mineral oil got into the synthetic oil, triggering a chemical reaction that created sludge, clogging the oil filter and making a full system replacement a nightmare. A friend of mine had it worse—he added a cleaning solvent to tackle carbon buildup, only for the oil film to break down, causing piston ring scratches. Don’t fall for online ‘quick fixes’—engine oil should only be of the correct type. Mixing in any foreign substance can trigger a chain reaction of issues. Always check the maintenance manual and stick to scheduled oil changes—that’s the right way.
