Atlas Copco XAS 185 Troubleshooting: Compressor Overheating

Why Is My Atlas Copco XAS 185 Compressor Overheating?

When your Atlas Copco XAS 185 portable air compressor starts overheating, it doesn’t just interrupt your jobsite, it can cause serious damage if left unchecked. Here’s a list of common overheating causes and exactly what to do to fix them, so you can keep working without unexpected shutdowns.

1. Insufficient cooling airflow

Blocked airflow around the compressor can lead to high operating temperatures, especially in hot or dusty environments.

  • Suggested action: Move the compressor away from walls, barriers, or other obstructions that block cooling air. Ensure enough space around all sides for proper ventilation, especially if multiple compressors are banked together. Keep doors closed during operation to maintain airflow design.

2. Oil cooler clogged externally

The oil cooler fins can become coated with dirt or debris, reducing heat transfer and causing oil temperatures to rise.

  • Suggested action: Inspect the oil cooler regularly. Use compressed air (blow from the inside out) or a soft brush to clean off dust and debris. Avoid using high-pressure water directly on fins to prevent damage.

3. Clogged oil filters

Restricted oil flow from clogged filters can reduce cooling and lubrication, leading to higher internal temperatures.

  • Suggested action: Replace oil filters as part of routine maintenance or sooner if oil differential pressure indicates clogging. Always use OEM-equivalent filters for best results.

4. Low oil level

Insufficient oil reduces both lubrication and cooling efficiency inside the compressor element.

  • Suggested action: Check oil level using the sight glass or dipstick when the unit is level and off. Top up with the recommended oil type if needed. Run briefly, then recheck to confirm correct level.

5. Thermostatic bypass valve stuck open

This valve controls oil flow through the cooler. If it’s stuck open, hot oil may bypass the cooler completely.

  • Suggested action: Remove and inspect the valve for sticking or debris. Clean or replace if necessary. Verify it opens and closes properly as oil temperature changes.

6. Broken or damaged fan blades

Damaged fan blades drastically reduce airflow across coolers and engine components, leading to overheating.

  • Suggested action: Inspect fan blades for cracks, chips, or missing sections. Replace the fan assembly if any damage is found.

7. Clogged oil separator element

A blocked separator element can increase system pressure and heat, impacting overall cooling efficiency.

  • Suggested action: Check and replace the oil separator element as recommended in the service schedule. Make sure the scavenge line is also clear to prevent oil build-up.

8. High ambient or recirculated hot air

Operating in high ambient temperatures or with exhaust air recirculating into the intake can elevate operating temps quickly.

  • Suggested action: Position the compressor so exhaust and hot air cannot recirculate into the cooling intake. Use additional shade or external fans in extreme heat if needed.

Final thoughts

Addressing overheating early prevents expensive repairs and keeps your Atlas Copco XAS 185 compressor running smoothly. Regular inspections, airflow checks, and oil system maintenance are key to long-term reliability.

Disclaimer: The information provided in this blog is intended for general troubleshooting guidance only and may not cover every situation or machine configuration. Always refer to your specific equipment’s manual and follow the manufacturer’s safety instructions. If you are unsure or uncomfortable performing any maintenance or repairs, consult a qualified technician. Air Compressor Services is not responsible for any injuries, damages, or losses resulting from the use of this information.