Is a Faulty Transmission Valve Body Considered a Major Overhaul?

[OMelanie]

Below are the key indicators that an engine requires a major overhaul: 1. Cylinder pressure difference: The cylinder compression pressure should meet the original design specifications. Use a tachometer and cylinder pressure gauge to check. If it does not meet the requirements, it is considered unqualified. The pressure difference between each cylinder should not exceed 8% of the average pressure of all cylinders. Measure with a tachometer, cylinder pressure gauge, or engine diagnostic analyzer. When the cylinder pressure of a Hyundai Elantra engine falls below its standard value, severe black smoke emission may occur. 2. Significant idle fluctuation: The engine should run stably at idle speed, with the speed conforming to the original design specifications. The speed fluctuation should not exceed 50 rpm. Conduct a running test with a tachometer or measure with an engine diagnostic analyzer. 3. Low power: The engine's maximum power should not be less than 90% of the originally designed rated value. Measure with a dynamometer according to relevant regulations. 4. Fuel consumption rate: The engine's minimum fuel consumption rate should not exceed the original design requirements. Measure with a fuel consumption meter. 5. Low torque: The engine's maximum torque should not be less than 90% of the originally designed rated value. Check with a dynamometer according to relevant regulations. Severe loss of working capacity should prompt a major overhaul.