What could excessive clearance at the crankshaft main bearings result in?

Excessive clearance at the crankshaft main bearings can lead to low oil pressure due to several reasons. When the clearance increases, it allows a larger gap between the bearing and the crankshaft, which can cause oil to escape more rapidly than it can be replenished. This means that the oil is unable to maintain the necessary pressure to effectively lubricate the engine components.

In a well-functioning engine, a certain amount of oil pressure is crucial for ensuring that oil reaches all parts of the engine, particularly under load. When the clearance is too large, the flow of the oil becomes less efficient, leading to lower pressure readings on the oil gauge. Low oil pressure can result in insufficient lubrication, potentially causing serious engine damage over time due to increased wear and tear on moving parts.

On the other hand, excessive clearance does not create high oil pressure or fluctuating pressures, as those scenarios are typically associated with other issues like blockages or pump failures. Additionally, aerated oil usually arises from other problems, such as improper oil levels or excessive foaming, rather than from clearance issues at the main bearings. Therefore, the outcome of excessive clearance directly contributes to low oil pressure in the engine.