Air compressors are central to applications in a range of industrial, commercial and residential settings – from pneumatic tools to machinery and HVAC systems.
Offering lubrication, protecting from wear, dissipating heat and acting as a sealing agent, air compressor oils – made by brands such as CPI Fluid Engineering – are key to keeping air compressors running as they should.
By the same token, regular maintenance and changing the oil are important – so when should air compressor oil be changed? This article outlines nine warning signs to look out for.
Unusual noises
When air compressors start to make knocking, grinding or rattling sounds, this could be a sign of inadequate lubrication.
Fresh oil creates a protective film between moving metal parts, reducing friction and noise. As oil degrades, it loses its viscosity and lubricating properties, causing metal-on-metal contact that produces unusual noises.
Ignoring these sounds can lead to accelerated wear and potential component failure. If a compressor becomes louder or develops new sounds, the oil level and condition should be checked immediately. Dark, dirty oil indicates it’s time for a change.
Overheating
An air compressor that runs hotter than normal is giving you a clear warning sign. Oil plays a crucial role in heat dissipation, carrying heat away from critical components. When oil breaks down, it loses this ability, causing operating temperatures to rise.
If an air compressor feels unusually hot to the touch or if automatic shutdown features are activating due to high temperatures, this is a warning sign. Regular oil changes help maintain proper heat transfer and prevent overheating that can damage seals, bearings and other vital components.
Refrigerant leaks
While refrigerant leaks are more common in refrigerated air dryers attached to compressor systems, they can indirectly signal oil problems. Poor lubrication can cause increased vibration and stress on the system, potentially creating or worsening leaks in connected components.
If refrigerant leaks coincide with declining compressor performance, old or degraded oil might be contributing to the issue. Address both problems promptly to prevent further damage and ensure efficient operation.
Tripping circuit breaker
If an air compressor repeatedly trips the circuit breaker, it’s often drawing more power than usual. This is a potential sign of oil-related issues. Degraded oil increases friction among moving parts, forcing the motor to work harder and consume more electricity.
This increased load can trigger protective circuit breakers. Before assuming an electrical problem, check the air compressor’s oil. Changing to fresh oil with the correct viscosity might resolve the issue and prevent unnecessary electrical repairs.
Burning smell
A burning odour coming from an air compressor is always a warning sign and requires immediate attention. This smell indicates overheating and potentially oil breakdown. As oil degrades, it can reach its flash point more easily, producing a distinctive burning smell.
When a burning odour is detected, the compressor should be turned off immediately. After allowing it to cool, check the oil’s condition. If it appears dark, has a burnt smell or shows signs of contamination, a complete oil change is necessary before resuming operation.
Decreased performance
One of the most common symptoms of oil issues is gradually declining performance. This may be when air-powered tools aren’t working as effectively, or the compressor takes longer to reach desired pressure levels.
When oil degrades, it can’t properly lubricate moving parts, causing increased friction and reduced efficiency. Regular oil changes can restore performance and extend the compressor’s useful life, giving air-powered tools the consistent pressure they need.
Increased energy consumption
If electricity bills are climbing without a corresponding increase in compressor usage, this may be due to old oil. Degraded oil creates additional resistance within the system, forcing the motor to work harder and consume more power to achieve the same results.
Monitoring energy consumption can provide an early warning of oil-related issues. Fresh oil reduces friction and helps the compressor operate as it should; saving energy and keeping down operational costs.
Loss of pressure
When an air compressor struggles to maintain consistent pressure or fails to reach the pressure levels it once did, worn-out oil could be affecting internal seals and components. Proper lubrication helps maintain seal integrity and component alignment.
Check pressure gauges regularly and note any declining trends. If pressure problems emerge despite having no apparent air leaks in the system, an oil change might restore proper functioning and pressure capabilities.
Oil leaks
Perhaps the most obvious sign that an air compressor needs attention is visible oil leakage. While this might indicate mechanical issues like worn gaskets or seals, it also means the compressor is losing its vital lubricant.
Regular inspection for oil puddles or stains beneath your compressor can catch problems early. Address leaks promptly, repair any mechanical issues and replace the lost oil with fresh lubricant of the manufacturer’s recommended type and viscosity.
