oscar
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- Aug 31, 2013
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I've noticed recently that a lot of people often neglect to change their oil at the stated intervals as recommended by the respective manufacturers.
In my oppinion, to understand it all you will need to have a fair knowledge of the ICE and emissions. On the power stroke, the expanding gasses pushing the piston down will leak past the pistons compression rings and as these are not a perfect seal, some unburned fuel and water (products of incomplete combustion) make their way into the the crankcase and mix with the oil in your sump. Over time, to keep it basic your oil will mix with this moisture and fuel which creates ''gunk'' which will collect at the bottom of your sump which is fine if you stick to the manufacturers recommended oil change intervals, the gunk will come out with the oil no bother. If you exceed this interval, the engine oil will get acidic after long use and will also lose the viscosity properties that are required to keep surfaces lubricated. The oil will also cause the filter to become less efficient and the bypass valve will open and the oil will no longer go through the filter and all the little contaminants will continue going through the engine causing main bearing surfaces and other metal-to-metal surfaces to "grind" to failure. Bearings will wear causing a larger gap between the crank surfaces and the bearings and the oil pressure will drop, then other parts will fail. The vital moment in every engine is when you start a cold engine. If there is a lot of contaminants settled in the bottom of the oil sump (which is where the oil pick-up is), all the solid contaminants will pass through the engine, again causing bearing surface failure.
This gunk will crystalise around the crankshaft, the camshaft and all their associated bearings making cold starts close to impossible. Eventually your big end bearings will have no lubrication, as well as your cylinder walls meaning that the piston rings will create so much heat due to the lack of lubrication as they move up and down on their respective strokes that the piston rings will basically weld themselves to the cylinder walls and to the piston crown itself in the worst case scenario.
I was always taught to change oil every 5,000 miles regardless of the manufacturers recommendations to prolong the working life of the engine. If we assume 5L of good oil costs around 35 pounds making that 3,500 pennies over 5,000 miles this equates to 1.4 pence per mile in oil costs.
In my oppinion, to understand it all you will need to have a fair knowledge of the ICE and emissions. On the power stroke, the expanding gasses pushing the piston down will leak past the pistons compression rings and as these are not a perfect seal, some unburned fuel and water (products of incomplete combustion) make their way into the the crankcase and mix with the oil in your sump. Over time, to keep it basic your oil will mix with this moisture and fuel which creates ''gunk'' which will collect at the bottom of your sump which is fine if you stick to the manufacturers recommended oil change intervals, the gunk will come out with the oil no bother. If you exceed this interval, the engine oil will get acidic after long use and will also lose the viscosity properties that are required to keep surfaces lubricated. The oil will also cause the filter to become less efficient and the bypass valve will open and the oil will no longer go through the filter and all the little contaminants will continue going through the engine causing main bearing surfaces and other metal-to-metal surfaces to "grind" to failure. Bearings will wear causing a larger gap between the crank surfaces and the bearings and the oil pressure will drop, then other parts will fail. The vital moment in every engine is when you start a cold engine. If there is a lot of contaminants settled in the bottom of the oil sump (which is where the oil pick-up is), all the solid contaminants will pass through the engine, again causing bearing surface failure.
This gunk will crystalise around the crankshaft, the camshaft and all their associated bearings making cold starts close to impossible. Eventually your big end bearings will have no lubrication, as well as your cylinder walls meaning that the piston rings will create so much heat due to the lack of lubrication as they move up and down on their respective strokes that the piston rings will basically weld themselves to the cylinder walls and to the piston crown itself in the worst case scenario.
I was always taught to change oil every 5,000 miles regardless of the manufacturers recommendations to prolong the working life of the engine. If we assume 5L of good oil costs around 35 pounds making that 3,500 pennies over 5,000 miles this equates to 1.4 pence per mile in oil costs.