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Sullair 185 Compressor engine oil overflows during use

Travs Thompson ยท 2022-10-14 22:52

I have a Sullair 185 Rotary Screw Air Compressor with a John Deer 4 cy diesel engine. The unit was make in the mid 80s. The engine oil started overflowing while the unit was operating. The engine oil does not appear to be diluted like it would be if fuel was getting into crankcase. The air compressor oil volume also does not appear to be going down. Does anyone know where this excessive oil could be coming from?

Replies14
  1. #1Tyler d4c2022-10-14 23:03

    Hows the coolant

  2. #2Travs Thompson2022-10-14 23:31

    Thank you, I will check in the morning. The level has not changed every time I have checked though this morning.

  3. #3mg23612022-10-15 05:21

    Where specifically is the oil flowing out on the engine? Pictures?

  4. #4Travs Thompson2022-10-15 16:10

    The oil is coming out of the breather vent coming out of the valve cover. Tyler the coolant level has not changed. HeavyEquipmentForums I am going to drain the oil down to full and run it again Monday. I think there is about 1 gal of extra oil in the crank case. Thursday morning the oil level was at the full mark.

  5. #5mekanik2022-10-15 17:45

    If the oil level is staying between the marks on the dipstick then I suspect you have a crankcase pressure issue that's pushing the oil out of the vent. It might not hurt to remove the valve cover, there may be a baffle covering the outlet on thew valve cover that has come unfastened.

  6. #6eastroad2022-10-15 23:17

    Does the oil seem to be diluted or thinned out with fuel? If the diaphragm in the fuel transfer pump goes bad, the fuel can enter the crankcase that way, leaking internally. That would be the first thing I would suspect on that JD engine.

  7. #7joe--h2022-10-16 01:20

    Just curious, what is the date on that oil filter? Joe H

  8. #8Travs Thompson2022-10-16 12:47

    The oil level went above the full line. It is staying above the full line and blowing the excess out through the valve cover breather vent house. It pushed quite a bit out. I will collect it tomorrow when we run it. I have a solid day of drilling left. The oil does not seem diluted. I will check out the fuel pump. The date is 8 16 22. We just service the machine. It has about 60 hrs on this oil change. We use Rotella T4 15w40

  9. #992U 34062022-10-16 15:03

    Something has to be dilluting it. Oil just doesn't magically appear. Generally the only 2 culprits are fuel and coolant. If you want to know for sure, send in an oil sample and they'll tell you what's getting in there.

  10. #1092U 34062022-10-16 15:05

    Another possibility is does this unit have an auxillary engine oil reservoir?

  11. #11Travs Thompson2022-10-16 23:38

    Exactly oil does not appear. I will check with our local fuel oil supplier to see if they can test the oil. That will tell the story. I don't see a remote oil reservoir. I also looked for a remote cooler but did not find one. I was suspecting that somehow the compressor oil was getting into the engine through a cooler but don't see a path. I so appreciate everyone's comments and ideas.

  12. #12Travs Thompson2022-10-18 09:15

    I appreciate the help from everyone here. We found the problem. The compressor side had a leak close to the vent hose. The oil was collecting in the hole in the dust/ dirt on the floor of the machine that the bottom of the vent hose made . Every time I pulled the hose up oil was dripping from it. The leak finally got bad enough we saw where it was spraying from. Again thank every one. This one had me stumped and very concerned. We had to stay head of the guy blasting rock this morning and there were not any large air compressors anywhere to rent.

  13. #13stinky642022-10-18 09:57

    Did you investigate the oil level issue? I have replaced several of those Deere lift pumps with the very same issue, leaky diaphragms.

  14. #14Travs Thompson2022-10-25 10:11

    I am going to replace the lift pump. Its been setting waiting for the next drill project. Very likely it is leaking. I am also thinking that I have low fuel flow. That will kill two birds with one stone.