air compressor bane: water condensing in crankcase oil

[ratbldr427]

Think about it, every thing with a crank case that hot/ cold cycles gets filled with water if it is not cooked off. The average car engine has lots of water condensing in the crankcase every start up but you never see it because the warm up is pretty quick and thermostats are set at 190. The cars from the '50's with 160 thermostats and short cycled would get sluged up pretty quick.
Our old plant had several well fed fire protection pumps. One was 150hp electric and the other 160hp Cummins marine diesel. When I started there new guy gets to run the pumps to test every Monday. The guy showing me the ropes said all you have to do is start the diesel ,check the pressure and for leaks and shut off and do the same for the electric.

I asked him how long have you been doing that ? "Since I've been here,Why?" Then asked him how often you drain the water out of the crankcase? He gave me a dumb look! I started running it to full temp and 5 min more and checked the oil , no signs of condensation.

 

[john.k]

You can get water shedding oils..........however ,is a motor detergent oil going white with loaded water a bad thing?.....When you drain the white ,all the condensation is gone ...........with a water shedding oil,you will find droplets and pockets of water coating the inside of the machine ,and causing rust............I use high detergent motor oils to reduce the water condensed inside tractor gearboxes that dont get hot enough to eliminate the water.

 

[ratbldr427]

I built a aluminum head 427 chev for a friends SK boat in the 60's. Hull weighed 450lbs. The coolent was a fresh water pick up with a restrictor in the outlet. I don't think the motor got over 150 deg on the test run. After we got back to the shop I pulled the v/covers to check the valve train. I was thinking damn this cover seems a lot heavier than I remember. The vc was filled with what looked like gray shaving creme . Crap, I thought for a moment we had blown a head gasket. I hooked it up to a hose and cut the water back until the temp got up to 180 or so and let it run for awhile watching the steam come out the breathers! Pulled the covers and every thing looked like new, oil clean.
Heat exchangers are the way to go but they were hung up on weight.

 

[john.k]

Years ago ,when I was at the hospital,the engineers had a Valiant car that was only driven around the hospital.....longest run would be 5 minutes......the oil was just like milk ,and just as thin.........once a year ,I would take it to the Govt .motor pool across town for its Safety Inspection ,and they would do an oil change while I was there.

 

[Peter S]

Any chance your compressor is in an enclosure which gets hot? It is not unusual for noisy compressors to be put outside in their own shed. If so, the inlet air should be taken from outside, not from inside the hot enclosure.

 

[steve-l]

Sorry boys, this is normal. Water will condense in the oil, but it does not matter. I have had this issue for 25 or more years with the same compressor.. It is still working perfectly. I do change the oil about yearly. It just is not a big deal.