Problem with oil - piston compressor.

[amron]

I have a piston compressor that I recently received. I've drained the oil and noticed that it's not the way oil (even used) should be. it resembles the oil the you find in a vehicles engine when the head gasket is blown and coolant mixes with the oil - by the color, it's not that thick. I've changed the oil twice, but I still getting the oil as can be seen in the picture (the white shape in the middle, is the glare of the sun. the color of the oil is the light brown/beige). the oil that I've put in is regular engine oil.

 

[Cobbler]

Condensation getting in the oil possibly?

 

[Erie Fred]

So your using detergent engine oil ?
Compressor oil is usually non-detergent.
And it looks like you need to run the compressor longer to heat the oil, and drive off moisture.

 

[Alan Reynolds]

My thoughts
The crankcases of these compressors have an open vent in the oil filler. We’ve had 100% humidity recently and every time the piston goes up and down, it draws in cold damp air which would mix with the oil as it’s a splash/dipper non pumped lubrication system.

 

[m_c]

As has been said, it's got moisture in it. I wouldn't be overly concerned.

 

[amron]

As has been said, it's got moisture in it. I wouldn't be overly concerned.

Thanx, but is there a way to remove the moisture?

 

[Erie Fred]

Please re-read post #3

 

[knighty]

what kind of compressor is it? bit industrial? hobby diy?

post photos?

 

[amron]

Please re-read post #3

Thanx for the reply. I've seen it before, I just thought there is a more "sophisticated" method.

 

[amron]

what kind of compressor is it? bit industrial? hobby diy?

post photos?

It's not a hobby diy, it's larger. I don't know who is the manufacturer of the compression unit, it seems an Italian one. the tank has a volume of 150 liters and it's powered by a 5.5hp three phase motor.

 

[Erie Fred]

Thanx for the reply. I've seen it before, I just thought there is a more "sophisticated" method.

Get rid of the old oil, install new non-detergent oil.
Run compressor, detergent oil left inside will mix with your new oil.
But there will be much less detergent.
Run compressor hard for at least 1/2 hour to bring the oil up to temp.
You might need to change it again in a few weeks.

 

[Seadog]

Detergent oil will gum up the Reed valves. The additives carbonise.

 

[Turbo]

Detergent oil will gum up the Reed valves. The additives carbonise.

I've been running my compressors for years on car engine oil with no problems.

I find that the big issue with compressor oil is that its normally a monograde SAE30 that turns to treacle in cold weather meaning that the compressor will not start, the motor sits humming & pops the fuse! Do that too many times & you could cook the motor! The SAE30 is fine in warm climates or heated workshops, definitely not suited to the UK climate!

I use multigrade 10-40 that is better suited to our climate.

 

[Turbo]

I have a piston compressor that I recently received. I've drained the oil and noticed that it's not the way oil (even used) should be. it resembles the oil the you find in a vehicles engine when the head gasket is blown and coolant mixes with the oil - by the color, it's not that thick. I've changed the oil twice, but I still getting the oil as can be seen in the picture (the white shape in the middle, is the glare of the sun. the color of the oil is the light brown/beige). the oil that I've put in is regular engine oil.

View attachment 381535

You could be getting air leaking past the piston into the sump, carrying water with it. See if the sump gets pressurised when the compressor is running.

 

[Alan Reynolds]

I've been running my compressors for years on car engine oil with no problems.

I find that the big issue with compressor oil is that its normally a monograde SAE30 that turns to treacle in cold weather meaning that the compressor will not start, the motor sits humming & pops the fuse! Do that too many times & you could cook the motor! The SAE30 is fine in warm climates or heated workshops, definitely not suited to the UK climate!

I use multigrade 10-40 that is better suited to our climate.

I run mine on the same multi grade. Never had a problem. I use the same oil in my lawnmowers.

 

[Barking Mat]

I think I slung 15/40 in our three phase compressor, when it had its 'I've been with this company 10 years and no-ones ever changed the oil in it' decennial oil change.

Still going strong, I drain down the tank, cough, anually, and get a half pint of water out of it.

The tank should have been replaced years ago, by law, but hey...

 

[brightspark]

i just use any engine oil in my comp. the pump is of a leyland bus so did run of the main engine oil which did many thousands of miles

 

[amron]

what kind of compressor is it? bit industrial? hobby diy?

post photos?

I believe that I found the pump info - https://windcompressorpumps.com/201...mpressor-pump-5-7-5hp-2-stage-model-bra6180v/
Please take a look at the oil level sight glass - the color of the oil.

 

[Erie Fred]

That looks like a "Roll-Air" pump.
Get that oil out of there regardless what you put back in there.
How is that uncovered electric switch box legal ? or are you working on it when the pix was snapped ?

 

[Seadog]

That looks like a "Roll-Air" pump.
Get that oil out of there regardless what you put back in there.
How is that uncovered electric switch box legal ? or are you working on it when the pix was snapped ?

Who cares? If it's a home workshop it's your responsibility.