What are the reasons for engine oil consumption?
2 Answers
Engine oil consumption can be attributed to the following specific reasons: 1. Poor valve sealing. Generally, if an engine burns oil, the first step is to check whether the valves and valve oil seals are functioning properly. Next, inspect the clearance between the piston rings and cylinder liners. Replacement may be necessary if issues are found. 2. Excessive clearance between the pistons, piston rings, and cylinder liners. This situation may require replacing the pistons, piston rings, lower cylinder liners, reboring the cylinders, replacing the valve and valve oil seals, grinding the crankshaft, and replacing the big and small end bearings. Essentially, all damaged parts of the engine need to be replaced with new components. After a major overhaul, the engine will require a break-in period similar to that of a new car.
Engine oil burning is a common issue I encounter, primarily due to internal component wear. If the piston rings age or break, the sealing performance deteriorates, allowing oil to sneak into the combustion chamber and burn. When the valve stem seals become as brittle as a cracker and split, oil drips down the valve stems, which is another headache. The turbocharger's sealing rings are also prone to failure first, and once damaged, oil escapes with the exhaust gases. Additionally, cylinder walls worn into a sandpaper-like texture or a stuck crankcase ventilation valve can cause a sharp increase in oil consumption. These problems usually result in blue smoke from the exhaust and a noticeable drop in power. It's advisable to regularly check the oil dipstick and head to the repair shop immediately if abnormal oil consumption is detected, rather than waiting until the engine completely fails.
