Why Atlas Copco G18 blows oil and smokes?


I have an Atlas Copco that was rebuilt a little over 1000hrs ago including a new air end.

I noticed the air inlet filter is wet with oil and when you shut the compressor off it will puff out a lot of white smoke from the air inlet filter.

Also when you open the manual drain you get a mix of oil and water.

We lent the compressor to another shop and they neglected to clean the cabinet air filter several times in turn running it hot.

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Jul 24, 2016
Inlet valve
by: Carl

Did you repleace the inlet valve when you refurbished the machine? Sounds like the oil is passing through it when you turn it off.

How do you normally turn it off? It is vital that you turn the compressors off by pressing the off button, some people like to hit the emergency stop which doesn't do them any good, if the compressor is onload when you do this, the inlet valve is open and the air pressure shoots hot oil into the air filter causing smoke and resulting in a wet air filter.

Also damaging the inlet valve, just get a service kit for the valve and you should be OK.

The oil in the tank sounds like it could be the separator filter needs replacing too.

Jul 22, 2016
by: Doug in s.d.ca

What color?

Is the oil in the drain cloudy mixed or settled out?

What oil is it? synthetic or petroleum?

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