Don't Be Alarmed If Your Pressure Washer Oil Looks Frothy While Running

Pressure washer being prepped for an oil change.
Loading... 135 view(s)
Don't Be Alarmed If Your Pressure Washer Oil Looks Frothy While Running

Pressure Washer Oil 5 Minutes After Use

After using your pressure washer, you may notice that the oil in the sight glass looks bubbly or frothy. This can be alarming, making you think water has somehow gotten into the oil. There is a simple explanation: pressure washer oil will become frothy from the high-speed operation of the pump.

Pressure Washer Oil Appearance While Running

It is completely normal for the oil to take on this foamy appearance while the pressure washer is running.

Pressure Washer Oil Appearance 12 Hours After Use

A few hours after shutting off the pressure washer, the air bubbles in the oil will dissapate and the oil will return to its regular appearance. So if you check the sight glass and see frothy oil, don't panic! Just let the pressure washer sit for a while after use. When you return and inspect it again, you'll likely see that the oil has settled down and looks normal once more.

The takeaway is that frothy-looking oil during and right after use does not necessarily mean that water contamination has occured. It is simply a result of the pump running. Give it time to settle before assuming there is a problem. Follow the manufacturer's maintenance guidelines and your pressure washer's oil should perform just fine.

If you still suspect that there is water in your oil, read here to see photos of milky pressure washer oil and learn how to clean out your pressure washer crankcase.