Air compressor blowing oil, fix?

[tncatadjuster]

Is there a easy way to hone and put rings and pistons? I have not run it low, just put many miles of air through it. Tank is in great shape due to maintenance. This oil usage started this year.

 

[bsaint]

Have you changed the air filters?

 

[tncatadjuster]

Yes in the past but I have not checked them since this started. Will do it tomorrow.

 

[sberry]

Take the head off, run it and see if oil pools on top of pistons.

 

[mikeceli]

Take the head off, run it and see if oil pools on top of pistons.

Are you gonna elaborate for the OP?

I'm guessing your pointing towards bad rings/cylinder walls.

 

[tncatadjuster]

Quick check of the filters show nothing out of order, it will be a while before I could pull the heads and look at the cylinder walls.

 

[sberry]

Yes, if it pools oil its coming past the rings.

 

[bsaint]

Also if there is an intake restriction it will do it too. But the air filters dont look that bad.

 

[pilotmotor]

also check that the crankcase is properly vented.

 

[Mamrak76]

What if the valves are not opening and the compressed air is bypassing the piston rings and entering the crankcase. Blowby made worse by the valves malfunctioning

 

[sberry]

Maybe but,,,, pull the head off and run it, see if it pools,,, head off means the problem is or isn't something else.

 

[jubilee]

also check that the crankcase is properly vented.

I have a couple 27 cfm gas powered compressors and the crankcase vent is about a 1/16” hole in oil fill plug. I check them regularly because it gets very messy very quickly if they plug up.

 

[tncatadjuster]

Thanks for all the replies, turns out it was the sight glass weeping oil and it was being blown all over by the air movement. As I tightened the glass it sheared the plastic threads. Will replace with a new one and give it another 19 years to start leaking.

 

[tncatadjuster]

What if the valves are not opening and the compressed air is bypassing the piston rings and entering the crankcase. Blowby made worse by the valves malfunctioning

Dead on...

I finally got time to look closer, the reason the sight glass was leaking was due to crankcase pressure, the treads were good but the air pressure was making it become loose. I removed reed valves that had some carbon cleaned and reinstalled, still blowing air out fill port. Cleaned again reinstalled no go, third time is the charm, I was using carb cleaner and finally got them to seal properly, I know to not bend them while inspecting.

I ran it to see if it was pooling oil and they stayed clean after 5 min of running.

All is good.