Hi everyone, so I have oil coming out the breather tube on the valve cover. Seems to run fine with no blue smoke or any issues at all. I took apart the cover on top of the valve cover to find the breather and there was nothing there to replace. Any ideas anyone? I would say bad rings, but it starts like a champ and no smoke. Thank you
The first thing I would check... Start the machine and remove the valve cover cap / oil fill cap. Some vapor / blow by is normal. Anything more than a little and you may have something going on inside. Check it out and let us know what you see. We'll go from there...
I have quite a bit of pressure coming out of the oil cap. The oil is clean and hasn’t really gone down to speak of yet.
What is the make on the engine and how many hours on the machine and engine?
2007 S185 with the v2003 kubota engine. Machine has 2650 hours.
I'm not familiar with that engine. It's probably a Tier 2 engine. Usually inside the breather cap there will be some screening or what looks like steel wool. Basically the oil mist settles on the strands and falls back into the engine when it builds up enough. What I usually do for engines that have breather tubes on them is use a water tube manometer to get the actual amount of crankcase pressure being generated. Rule of thumb is that there should be no more than one inch of water with the engine under full load at high idle. I usually hook up the manometer by pulling the dipstick and securing the hose over the tube with electricians tape.
Sure you don't mean Kubota V2003?
Yes that is what I mean kubota v2003 engine tier 2.
That doesn't sound good. Worn piston rings perhaps..
I'd look at pulling glowplugs and doing a leakdown with air to see if it's blowing past rings or a headgasket into the crankcase
Could you give me a little insight on exactly how I go about doing that? What kind of tools are needed? Thank you.
Ok so I did a compression test on all cylinders and they came in at just over 400psi per cylinder. Could there be a blockage somewhere??
Is the vapor coming out of the breather actually oil? I've seen engines with plenty of vapor that was actually engine coolant. Sometimes in the transition time between winter and spring you will get water vapor from condensation inside the engine if the machine has been sitting for a long period of time. That's part of why I mentioned checking crankcase pressure and materials that are supposed to be in the breather that I mentioned in an earlier post.
It is actually oil that comes out only when the machine is forced. When i take the cover off the oil fill on the valve cover there is alot of pressure coming out at idle. I took the blowby hose off the valve cover and put my finger to see how much pressure is coming out and there isnt much. What kind of manometer do I need? Thanks
Those are good compression numbers, have you checked that the little diaphragm under the breather cover isn't torn or sticking? We've had a few Kubotas (not a V2003 specifically) that would start dribbling oil out of the tiny weep hole and needed them replaced. Sometimes they get gummed up with engine condensation (coffee creamer) and will stick and let oil splash through. Pulled ones that looked fine, installed the new one and problem went away. For a manometer, an old school Yellow Jacket dial type will do you fine (and not break the bank like the digital models). Looked real quick and the model I have is a 78060. As far as a leak down; There are adapters and a gauge set you can buy for getting real numbers. But the quick and dirty way is an air compressor and a rubber tipped air nozzle. Pull glow plugs, either bar engine over to close valves on each cylinder or take off the valve cover and loosen all your rockers (which is actually faster and easier), and blow air in through the glow plug hole. With valves closed the air should stay put and blow back out when you pull the nozzle away. If you can hear air escaping through intake or exhaust, it's valves. If you hear it through the oil fill or radiator, it's (most likely) a head gasket issue.
That was the first thing that I checked for. I had a mini excavator with a Kubota engine that kinda did the same and I changed the diaphragm with spring and all was well. Unfortunately this does not have a diaphragm or spring. It just has an o ring with a cover. Looking at the parts breakdown through bobcat, that’s all it shows. Thank you everyone for the assistance!
Also check to see if the muffler on those machines are clogged. I’ve had one or two that were, and the blow by subsided greatly when muffler was disconnected.