High probability of leaks
Over-lubrication increases the possibility of leaks that necessitate replacement of items such as seals, hoses, air filters or vents among others, as well as other problems stemming from poor operation of these items.
Higher energy cost
When more lubricant is added to a machine than is necessary, the tribological conditions of that oil change, which can lead to a deviation in the optimum lubrication point and to a higher energy cost. A good example of that is a case in which a thermal motor, intended to work in a particular excellent lubrication point, receives more lubricant than is necessary. The oil lowers its temperature and, as a result, it increases its viscosity. Then more energy is required to move the machine, with the corresponding increase in energy cost that that brings with it.
Gathering environmental dirt
In the case of solid lubricants, a consequence of an excess of lubrication is that a part of this lubricant may become exposed to the environment, which means that it can gather environmental dirt that goes on to form part of the system.
Heating and chemical degradation
A variation in the quantity of the lubricant that is supplied can lead to an increase in temperature, thus changing the lubrication conditions and hindering the renewal of the lubricant in the critical areas. This will generate accelerated oxidation by chemical degradation and anomalous wear of the rotating items. The direct consequence is that the whole tribological system will eventually fail.
Damage in the joints
Lubrication in excess also has a negative impact on the state of the joints. When there is an excess of lubricating oil, the pressure rises in the seals, which makes them deteriorate and break. When this happens, both water and dirt can find their way into the mechanical system. Because of this it may be necessary to take corrective action on all of the machine.
Failures in electric motors caused by an excess of lubricant
An excess of lubrication in an electric motor causes certain phenomena that can lead to catastrophic failures. For example, an excess of lubrication can mean that the lubricant penetrates into the stator. This means that it reaches the winding and this leads to a grounding and, in the worst scenario, if there is no grounding, an excess of temperature.
A failure associated with over-lubrication in the fan is of less importance than one that occurs in the stator because, whether or not grounding occurs, it conditions the kind of failure that will happen in this item. When there is grounding, a catastrophic electric failure occurs with total stoppage. When there is no grounding, the failure is not catastrophic, but it has an important effect on the operation.