Need help with compressor

[snonut]

Hi all. First time poster with an air compressor problem. I am hoping the wide array of knowledge on GJ can help out.
I have a Quincy 2-stage compressor that unfortunately has to be in my unheated shop. It doesn't get a lot of use in winter, since my shop is unheated, but I might need it in a tire emergency. It "knocks" when first starting after sitting over night. Noise quits after 6 or 8 revolutions of the crankshaft, telling me the oil is probably too thick. My question is what can I safely dilute it with?
A friend of mine that is an HVAC tech suggested mineral oil. Not sure about that, either. If I could find the right oil, I would just change it completely (ever tried looking for 10 or 20 wt synthetic, non detergent compressor oil?). Any suggestions?

 

[bsaint]

I would drain it and run a 10w depending how cold it gets. That's what we run in machines mounted on trucks in the winter.

 

[Advan]

Amsoil oil sells 20W compressor oil by the quart. I would just put in some Mobile1 5w30 though!

 

[Zeke]

You need a good quality oil, not some stuff from HF. Running light weight in the winter is common practice. But, if the machine gets a lot of use, the LW might be too thin when the compressor gets hot. I too would think multi weight is a good answer although I never see it recommended.

 

[my58dodge]

I bought a new 2 stage Quincy earlier this year, and I too run it in an unheated garage in Ohio. After the first 2 hours of use I drained the oil and refilled with Quin-Cip D synthetic. This is a diester synthetic compressor oil and runs about $24.00 a quart, and I had to order it through a Quincy dealer. My owner's manual temp chart lists it for use from 10 degrees F to 110 degrees F. A side note NEVER put automotive detergent oil in an air compressor!

 

[wild cowboy]

you don't need to dilute it at all, just buy any name brand 0W-20 or 0W-30 synthetic motor oil and all of your problems will be solved

don't believe the old wive's tales about only using compressor oil in compressors, oils have really improved in the last 10 years!

 

[wild cowboy]

You need a good quality oil, not some stuff from HF.

Exactly!

Running light weight in the winter is common practice. But, if the machine gets a lot of use, the LW might be too thin when the compressor gets hot. I too would think multi weight is a good answer although I never see it recommended.

Zeke, although I consider you one of the top 10 most knowledgeable folks on GJ (out of 1000's of members here) you have fallen victim to an old bit of misinformation about how oils work and thick vs. thin etc. - so I am hoping you (and everyone) will read Motor Oil 101 at BobIsTheOilGuy.com

a quote from the technical article:

"The greatest confusion is because of the way motor oils are labeled. It is an old system and is confusing to many people. I know the person is confused when they say that a 0W-30 oil is too thin for their engine because the old manual says to use 10W-30. This is wrong.

More confusion occurs because people think in terms of the oil thinning when it gets hot. They think this thinning with heat is the problem with motor oil. It would be more correct to think that oil thickens when it cools to room temperature and THIS is the problem."

 

[MacMcMacmac]

DeVilbiss didn't recommend anything over 20W until the ambient temperatures were over 100F.

 

[marinusdees]

The reason for non detergent is detergent is hard on sleeve bearings. Tends to eat the material. Ask an electric motor repair man.

 

[wild cowboy]

DeVilbiss didn't recommend anything over 20W until the ambient temperatures were over 100F.

This just goes to show that even compressor company mechanical engineers don't understand motor oil! - that is why everyone should read that article!

 

[CNGsaves]

The reason for non detergent is detergent is hard on sleeve bearings. Tends to eat the material. Ask an electric motor repair man.

^ ^ Partly correct. The reason that non-detergent oil is best in the typical oil splash compressor is because non-detergent oil does NOT SUSPEND contaminants. It lets them drop to bottom of crankcase. This is same theory after overhauling a car engine to run break-in non-detergent oil to let any metal shavings of bearings to fall out to bottom of crankcase and get quickly drained out with the short interval first oil change.

A top-of-the-line Quincy compressor with oil pump actually is much like auto engine that it will be fine with today's superior "motor oil" like Mobil 1 synthetic, Pennzoil Platinum, etc. . . . . . after the break-in period is over and non-detergent oil is drained.

However, for run-of-the-mill oil splash compressor, using non-detergent oil is likely best practice as you don't want contaminants suspended and staying up in wear zones of bearing races, wrist pin bearings, etc. Yet, the quality of these new synthetic oils are so great, there is likely no measurable effect on long-term reliability.

Moral of the Story . . . . no cheap **** compressor oil from Harbor Freight or generic motor oil from the Dollar Store !!

 

[wild cowboy]

once you change the initial oil and get the initial "break-in" oil out, then change the oil again in about a month to have it super clean, then there doesn't tend to be contaminants, suspended or otherwise.

It's not a high rpm automotive engine with combustion contamination and wear from high speed operation and high temps, it is a low speed pump with virtually zero wear happening throughout its life!

 

[snonut]

Thanks for all the replies. I just ordered a couple quarts of Amsoil 20w synthetic compressor oil. Will do a complete change next week when it arrives.:beer