What causes engine oil go bad quickly?

High ambient temperatures can make engine oil to degrade faster necessitating prompt routine oil maintenance.

There are some maintenance practices or lack of maintenance that causes the engine oil to degrade before it gets to the normal oil change time that is in line with the manufacturer oil change interval.



1. Allowing excessive dust to go into the engine

The environment in some countries are very dusty. Due to this, quality air filtration is required to keep the engine in good shape. Very dusty environments cause air filter to get clogged on time. When the filter is overdue for replacement and it is not changed, dust can enter the engine more easily, contaminate and degrade the oil faster.


2. Use of substandard oil filters

Substandard engine oil filters have become widespread over time. The filtration qualities of these substandard oil filters are not as good as that of OEMs or good quality ones. Some people fall for this as they prefer to buy the cheaper product. These substandard oil filters are not able to filter every micro particles (like little particles of dust, iron fillings, carbon) which causes the oil to degrade fast.

Poor maintenance culture

Some mechanics are known for bypassing or condemning systems that should be fixed and made to work. For Instance, when emission systems are not properly working, the engine oil might get polluted quickly. Another practice that can cause fast oil degradation is the running of radiator cooling fan at its maximum speed always by doing a direct power connection to the power source. This causes the oil not to reach its normal operating temperature. When moisture in the engine oil is not burned off by allowing the engine to reach its operating temperature, the oil degrades faster.


Lack of proper emissions check

As stated earlier, a car with more emissions will contaminate the oil faster, especially with carbon deposits. A typical example is when there is a leaky injector, if it is much, fuel can dilute the engine oil and this can have a catastrophic consequence on the engine.


Usage of substandard air filters

Very cheap and substandard air filters are not able to filter dust particles like the original equipment manufacturer (OEM) types. The more the amount of contaminants in the engine oil, the more its level of degradation.

It's also worthy of note that if an engine overheats seriously, the engine oil should be replaced as the excessive temperature may cause the oil to degrade to a certain level that some of it's additives would have broken down due to high temperature. Think of oil flash point.

For these reasons, recommended oil change intervals should be strictly adhered to by car users else they risk premature engine wear or engine damage.