Let’s talk about engine oils

oils.
We will start by tackling basic issues such as the main uses of oil.
The motor oil’s main use is to protect the engine by lubricating its moving parts. However, for this to happen oil needs to circulate quickly during start-up to avoid engine wear.
Oil is also designed to handle a variety of contaminants, from liquids and acidic combustion by-products and dirt particles. The oil helps by removing abrasive particles as it passes through, but it cannot catch fuel dilution and other liquid contaminants. That’s where oil additive takes over.
All detergent type motor oils contain detergent and dispersant additives, which suspend external contaminants and combustion by-products. That is why your oil may look dirty when you check it. Invariably, the oil and additive would have outlived its intended lifespan hence causing the oil itself to degrade resulting in oxidation or thickening of the oil.
There are no hard and fast rules as to when oil change should be effected, as there are many variables to take into account. These include driving habits, the ignition and engine timing, fuel injection or carburettor adjustment, air cleaner service and general mechanical condition of the engine. However, oil should be changed before its contamination levels reach a point where engine damage could occur.
The manufacturer’s guideline is the modus operandi that should be your guiding principle. In the case of severe operations this will require more frequent oil and filter changes.
During short trips or cold weather the engine may not get a chance to warm up and boil off moisture and this leads to acid developing in the oil. Since the engine is partially cooled by airflow, engine temperatures tend to increase when idling. This makes the engine work harder and increases the temperature. High temperatures can lead to oxidation and viscosity changes in the oil.
When driving on dust or sandy roads, abrasives can get past the air filter and into the oil system. As the wear condition of the engine deteriorates, the amount of blow-by to the crankcase increases. Blow-by is when combustion gases escape between the piston rings and cylinder walls instead of going out of the exhaust system.
l Let’s meet for more titbits from Obel next Friday. Contact us and get in touch with Mr G. Mbeya 0774 215 505. Proudly Zimbabwean.