What may be the effect of too low oil level in the combustion engine?
Show the correct answer
Correct answer
B. Wear of the crankshaft, pistons and valves.
Explanation
In the photo you can see a pulled-out engine oil dipstick with a red handle, in the engine compartment of a lorry. Too low an oil level in the engine may cause seizure of the crankshaft journals, the bearing shells and the pistons - answer B.
The Road Traffic Act requires a vehicle to be maintained so that using it does not endanger safety and does not expose anyone to harm. Engine oil separates metal parts that work against each other with a thin film of oil and takes heat away from them; when there is too little oil, the pump starts to draw in air, the film breaks, and the crankshaft journals, bearing shells and pistons run "dry" - metal welds to metal and the engine seizes. The oil pressure then falls, it does not rise (answer A), and the warning light comes on. The engine temperature does not fall either (answer C) - on the contrary, it rises, because oil provides part of the cooling. In a lorry, seizure means a major engine overhaul, which is why you check the oil level during the daily check, with the engine cold and the vehicle on level ground.
Legal basis: Art. 66 para. 1 point 1 of the Road Traffic Act (Prawo o ruchu drogowym)