Air compressor sounds like its going to throw a rod

[junkyardjeff]

I got a over 20 years old 220 volt Campbell Hausfeld 5 HP with 60 gallon tank air compressor that when all the air is drained it sounds like its going to throw a rod but after the tank fills up it starts to sound somewhat normal,anybody else have a compresor that does the same and is it normal to sound like that with no load on the compressor.  I cant remember what it sounded like when it was new but the oil needed changing so I put in some thicker oil for the warmer months,the oil did have a metallic look to it when it came so its probably worn a bit but I dont want to put a new compressor on it just yet so I hope it holds out for a couple more years before it blows up.

[34ford]

We have an old one at work that has twin belts on it and it starts sounding that way when the belts are getting loose. Tighten them up and it quiets down.

[wayne petty]

very few air compressors have an oil pump....  most have splash or dip oiling for the rod....

putting in thicker oil may not help...    30 weight non detergent oil...

in cold weather... sub 0 areas...   one might talk to the compressor repair about running something like mobil One...

you might check for loose belts... that will make a racket...  

check for a loose head....    with the power turned off at the circuit breaker... and locked out if you are in a place with other people...      rotate the compressor by hand...   see if you feel any looseness in the rod...  feel if there is any looseness in the drive wheel to the shaft...

it is possible that the reed valves are going...   or have been slapping the head surface so hard that they have left dents...

it is also possible that the reed valves or check valves are cracking or failing...


i have also had the tubes from one head to the other crack near the tube nut...  letting out a ton of noise...


you can use a broomstick to the area in front of your ear to isolate mechanical noises...


if you have a something failing... you might hear the check valve at the tank slamming open and closed as only one cylinder is pushing air...  so the valve pops open.. then slams closed... then open again...

it is possible for the tank check valve springs to fail after several decades...