Air Compressor Oil - Cold Weather Suggestions

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Dec 18, 2007
Madison, Wisconsin
I've got a Harbor Freight 21 gallon compressor. It does not like starting up in cooler weather, I usually have to cycle the start/stop lever back and fourth a couple seconds at a time to keep the reset from popping. After several cycles, things loosen up and away it goes. It will start on its own without throwing the reset. Are there different oils I could consider to get things moving better when cold? Right now, I just have SuperTech 30W ND in it. Or is this just something I'm going to have to resign myself to during winter? I understand it's not the best compressor, but it works for what i need. Unless it's cold.....
Always make sure it is starting from ZERO pressure when it is cold. If that is't what's going on.... something else is wrong (bad capacitor?)
I've been using Redline PolyComp 30W in my similar sized Craftsman compressor for about 15 years. Always fires up without tripping the reset or breaker even when I lived in Michigan and it was as cold as 0F no issues. Obviously still no issues here in Florida I change it every 5 years as the compressor doesn't run a ton.
I don't think the oil is to blame. There's something wrong electrically - it should start just fine, or MANY OTHERS with the same or similar compressor would be complaining about it (and they don't................ so there) It's just that you got a bad one, that's all.
I have the same air compressor. The manual that came with mine recommends 30wt when it's warm out and 10wt in the cold so that's what I've been doing. Tractor Supply sells plain non-detergent 10wt oil. I think once I run out of what I have currently I will probably just run a 5w30 or 10w30 synthetic in it year round though.
Originally Posted By: Linctex
Always make sure it is starting from ZERO pressure when it is cold. If that is't what's going on.... something else is wrong (bad capacitor?)
It was starting at zero pressure. I pulled the relief valve to double check. It does look like starting problems are either related to the check valve (probably not an issue since there was no pressure in the tank) or the capacitor. I guess the capacitor is easy enough to replace if I need to. It got worse the colder it got, and is getting better as temps are increasing. I guess I should have RTFM. I didn't even realize that the 10 ND oil was specified for cold weather. That probably would have helped I bet. I see Redline makes one, that might be the easiest just to order.
Best recommendation for for cold weather start up you cannot beat Amsoil PCK 30/40 avalible in qts not cheap but for all weather and more so cold weather it’s tops. Yes absolutely the problem you are having is in direct correlation to cold weather.
is it plugged directly into a wall outlet with stout wiring? air compressors in the cold take some serious grunt to start.. switch to a syn. oil.
It's plugged directly into the wall. I can't see the wiring, but the rest of the house is done in 14/2 romex. So I have to assume the garage is too. I'm going to do the synthetic oil change. Just need to decide if I go with the straight 10 oil, or do a 10-30.
I hooked mine up to run 220 volts. Problem solved. I don't know if that is an option on yours though.
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I have a small 4 gallon Campbell Hausfeld compressor. CH actually recommends using Mobil 1 5w30 in it, although the small bottle of oil they included with it is a non-detergent 30w. I used the included oil, and it was horrible trying to start it in cold weather. It tripped the breaker almost every time. After the break-in period, I drained that oil out and switched to Mobil 1 5w30. Night and day difference! It starts up no problem even on the coldest days. Bottom line: drain that straight weight oil out and fill it up with a 5w30 synthetic oil.
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