The long-term non replacement of engine lubricating oil poses great harm and can be regarded as the "invisible killer" of engine wear. The following are specific impacts and potential consequences:

1. Decreased lubrication performance exacerbates mechanical wear

Oil film failure: After aging, the viscosity of lubricating oil decreases, making it impossible to form an effective oil film on the surface of metal parts (such as pistons, crankshafts, camshafts), resulting in direct friction between metals and accelerating wear.

Key component damage: Scratches or even cylinder pulling may occur on crankshaft bearings, cylinder walls, and other parts. In severe cases, the engine may require major repairs.

2. Carbon and oil sludge accumulation

Oxidative deterioration: Lubricating oil oxidizes at high temperatures to form gum and carbon deposits, blocking oil passages and reducing oil supply.

Formation of sludge: Impurities mix with old oil to form sludge, which adheres to the interior of the engine (such as the oil filter and oil pan), affecting heat dissipation and lubrication efficiency.

3. Risk of engine overheating

Reduced heat dissipation capability: Deteriorated lubricating oil has decreased fluidity and cannot effectively remove engine heat, which may lead to local high temperatures, causing detonation or component deformation.

4. Corrosion caused by acidic substances

Acidic by-products: Lubricating oil oxidizes to produce acidic substances that corrode metal components (such as copper sleeves and aluminum parts) and shorten engine life.

5. Increased fuel consumption and decreased power

Increased frictional resistance: Insufficient lubrication leads to an increase in engine running resistance and fuel consumption.

Power attenuation: Carbon deposition and wear will reduce compression ratio, affect combustion efficiency, and weaken power output.

6. Risk of sudden malfunction

Oil pump blockage: Oil sludge may clog the oil pump filter, causing fuel supply interruption and leading to serious malfunctions such as engine tile sticking and stalling.

Surging maintenance costs: Long term neglect of oil changes may result in the need to replace core components such as crankshafts and cylinder blocks, with maintenance costs far exceeding regular maintenance costs.

How to avoid it?

Follow the manufacturer's recommendation: Change the engine oil regularly according to the maintenance manual requirements (usually every 5000-10000 kilometers or 6-12 months).

Choose the appropriate engine oil: Choose the correct model (such as 5W-30, 0W-20, etc.) according to the climate and driving conditions.

Check oil quality: Regularly test with oil test strips. If there is layering, impurities, or severe blackening, replace immediately.

Synchronize replacement of machine filters: Ensure filtration efficiency and avoid old oil contaminating new oil.

Tip: Even if the mileage is low, the oil will oxidize and deteriorate over time. Do not judge the oil change cycle solely based on mileage. Regular maintenance is the key to extending engine life!