So do I pescador, sorry I thought you were thinking along the lines of the pump, its ironic because I actually started doubting the regulator this morning, and wondered about the pump and "cavitation" causing the bubbles - it just sort of popped into my head, but then I remembered reading here the pump was a sort of injector, so it was almost impossible.
Air bubbles in the oil........
- Thread starter widget
- Start date
Please register or login
Welcome to ScubaBoard, the world's largest scuba diving community. Registration is not required to read the forums, but we encourage you to join. Joining has its benefits and enables you to participate in the discussions.
Benefits of registering include
- Ability to post and comment on topics and discussions.
- A Free photo gallery to share your dive photos with the world.
- You can make this box go away
So do I pescador, sorry I thought you were thinking along the lines of the pump, its ironic because I actually started doubting the regulator this morning, and wondered about the pump and "cavitation" causing the bubbles - it just sort of popped into my head, but then I remembered reading here the pump was a sort of injector, so it was almost impossible.
Widget, a thought just occurred to me, have you replaced the drive belt for the cam shaft recently?
Craig
Craig
Ok, I was just thinking of an improperly aligned cam shaft causing the oil pump to not inject at TDC on the 4th stage piston. The only "timing" (sort of) issue with the K14.
Craig
Craig
Okay, well you wont believe this but - we still got the froth.!
So in point we can eliminate the oil regulator as an issue.
I am now going full circle backwards and saying its dud valves - new, but dud.
My theory is just based on a lot of frustration and stripping the fourth stage but is as follows.
The fourth stage is allowing air through into the oil sight glass as soon as air pressure in the stage overcomes oil pressure (60bar) because we have no delivery of air - dud valves.!
We can hear a sort of click, click just beofe the oil froths which makes me think its the piston not getting sufficient pressure to operate so its clicking slightly like on start up.
Now my only issue is I dont know which one is faulty, suction or discharge, or both - my gut feeling is the discharge valve.
Its a matter of pride now chaps, us against the compressor (hah hah) - this thing is just not gonna beat me. Any ideas on this theory.?
So in point we can eliminate the oil regulator as an issue.
I am now going full circle backwards and saying its dud valves - new, but dud.
My theory is just based on a lot of frustration and stripping the fourth stage but is as follows.
The fourth stage is allowing air through into the oil sight glass as soon as air pressure in the stage overcomes oil pressure (60bar) because we have no delivery of air - dud valves.!
We can hear a sort of click, click just beofe the oil froths which makes me think its the piston not getting sufficient pressure to operate so its clicking slightly like on start up.
Now my only issue is I dont know which one is faulty, suction or discharge, or both - my gut feeling is the discharge valve.
Its a matter of pride now chaps, us against the compressor (hah hah) - this thing is just not gonna beat me. Any ideas on this theory.?
pescador775
Contributor
- Messages
- 2,652
- Reaction score
- 11
Valves are not the problem.
Have you checked the oil filter? There should be a small "bulge" in the oil pump discharge pipe, that would be the filter. Oil starvation could be a problem and would fold into my theory about the function of the regulator and cylinder. A loss of oil film on the cyl wall could explain the clicking sound.
Have you checked the oil filter? There should be a small "bulge" in the oil pump discharge pipe, that would be the filter. Oil starvation could be a problem and would fold into my theory about the function of the regulator and cylinder. A loss of oil film on the cyl wall could explain the clicking sound.
Could be Pescador, I havent checked the oil filter, how do you even do that? I have seen the bulge in the pipe, but it looks like a press type arrangement which cant be opened.
The clicking sound could very possibly be a loss of oil, (likely is) but I would say its because the air is overcoming the oil and blowing it out of the piston liner back into the sump and of course the oil glass - hense my theory of no air delivery via the valves.
Oil pressure now is better than I have ever seen it, dead steady at 60 bar and no fluctuations, even when fully frothed, oil pressure remains constant, however I fear the pressure is partly air.
Something I have noticed and it may be significant is that when you turn the machine off, oil pressure remains at 6 bar, whereas on the other machine it drops immediately to zero, - which indicates there is air trapped / been fed into in the system and taking over the oil pressure.
We checked this by releasing pressure on the oil regulator screw which immediately allowed more air into the sight glass and dropped the oil pressure by an equal amount (the machine is off) if we realese all the pressure and then retightening the oil adjuster and wait a few minutes, the oil pressure gauge signals a rise in pressure again which is air (not oil) passing through the system, there can be a build up of air over a lengthy period of say three or four complete releases via the oil adjusting screw - I am sure this air is the problem, we just cant find where its coming from.
If we run the machine with the stop cocks OPEN so it dos not build up pressure beyond 60 bar, there is no frothing, no clicking, nothing, but close a stop cock (increase air pressure) and immediately the clicking starts and the bubbles start forming in the sight glass, indicating to me air pressure is overcoming the 60 bar oil pressure.
I am stumped to be honest, I am really at a loss, I cant think of anything else to mention that can assist in the diagnosis, or do anything else except change filters, although I am doubtfull this could be a problem.
The clicking sound could very possibly be a loss of oil, (likely is) but I would say its because the air is overcoming the oil and blowing it out of the piston liner back into the sump and of course the oil glass - hense my theory of no air delivery via the valves.
Oil pressure now is better than I have ever seen it, dead steady at 60 bar and no fluctuations, even when fully frothed, oil pressure remains constant, however I fear the pressure is partly air.
Something I have noticed and it may be significant is that when you turn the machine off, oil pressure remains at 6 bar, whereas on the other machine it drops immediately to zero, - which indicates there is air trapped / been fed into in the system and taking over the oil pressure.
We checked this by releasing pressure on the oil regulator screw which immediately allowed more air into the sight glass and dropped the oil pressure by an equal amount (the machine is off) if we realese all the pressure and then retightening the oil adjuster and wait a few minutes, the oil pressure gauge signals a rise in pressure again which is air (not oil) passing through the system, there can be a build up of air over a lengthy period of say three or four complete releases via the oil adjusting screw - I am sure this air is the problem, we just cant find where its coming from.
If we run the machine with the stop cocks OPEN so it dos not build up pressure beyond 60 bar, there is no frothing, no clicking, nothing, but close a stop cock (increase air pressure) and immediately the clicking starts and the bubbles start forming in the sight glass, indicating to me air pressure is overcoming the 60 bar oil pressure.
I am stumped to be honest, I am really at a loss, I cant think of anything else to mention that can assist in the diagnosis, or do anything else except change filters, although I am doubtfull this could be a problem.
pescador775
Contributor
- Messages
- 2,652
- Reaction score
- 11
Remember what I said about oil being incompressible. It is this characteristic which causes the gauge to drop to zero immediately. Reserve oil in the plenum has no pressure, only volume. Air bubbles do not act like that. As air/oil mixtures bleed down the pressure drops but some pressure persists after the regulator valve closes because of the elastic nature of air which causes it to expand even as the pressure is dropping.
If the volume of oil is insufficient, according to my theory of operation, air will fill the void and the pressure gauge will not know the difference. It just measures pressure and does not care what the source of the pressure is. Well, it might hiccup now and then.
The oil filter is sealed inside the pipe. Disconnect the pipe and blow through it. The old type filter is a loose weave screen which does not easily clog. The new type filter is a porous element which is, or should be, more susceptible to clog. It sounds like your compressor has the old type filter screen but the test should be done regardless. If bad, the old type filter, pipe and all, must be cleaned or replaced. Cleaning would consist of blowing solvent and compressed air into the pipe. Drawings which I have seen of the new filters show the element to be replaceable.
If the volume of oil is insufficient, according to my theory of operation, air will fill the void and the pressure gauge will not know the difference. It just measures pressure and does not care what the source of the pressure is. Well, it might hiccup now and then.
The oil filter is sealed inside the pipe. Disconnect the pipe and blow through it. The old type filter is a loose weave screen which does not easily clog. The new type filter is a porous element which is, or should be, more susceptible to clog. It sounds like your compressor has the old type filter screen but the test should be done regardless. If bad, the old type filter, pipe and all, must be cleaned or replaced. Cleaning would consist of blowing solvent and compressed air into the pipe. Drawings which I have seen of the new filters show the element to be replaceable.
windyairman
Contributor
- Messages
- 198
- Reaction score
- 43
Hi
sounds as you are not having much luck with this unit & have done most things.
How about changing over the cylinder head from the other unit that has not got the fault.
I have had a fault some time ago,the head had a slight mark on the seat between valve & head.
Also are you sure that you are jacking the discharge valve down on to its seat in its head ?
The tool that you used to remove the intake valve from the head.Did it fit the new intake valve 100% ok?
May be if you did not have the new tool that the valve is not down tight on its seat.
Older type tool has the pins 9.50mm across pins & is gold finish new type is 10.63mm & is silver finish.
Is your oil pump belt or chain drive?
Do you know the make of your oil pump? it will be on the oval plate on the pump.
Also try to change over the oil pumps if all else fails.
Best of luck as we all want to put this thread to bed
sounds as you are not having much luck with this unit & have done most things.
How about changing over the cylinder head from the other unit that has not got the fault.
I have had a fault some time ago,the head had a slight mark on the seat between valve & head.
Also are you sure that you are jacking the discharge valve down on to its seat in its head ?
The tool that you used to remove the intake valve from the head.Did it fit the new intake valve 100% ok?
May be if you did not have the new tool that the valve is not down tight on its seat.
Older type tool has the pins 9.50mm across pins & is gold finish new type is 10.63mm & is silver finish.
Is your oil pump belt or chain drive?
Do you know the make of your oil pump? it will be on the oval plate on the pump.
Also try to change over the oil pumps if all else fails.
Best of luck as we all want to put this thread to bed
pescador775
Contributor
- Messages
- 2,652
- Reaction score
- 11
It's 10 pm in SA, do you know where your compressor is? Heh.
Yeh, Windy, that is about all that was left that I could think of, too and we're really scraping bottom, it seems. Well, the cyl head thing is new and did not occur to me. We're all in suspense.
Yeh, Windy, that is about all that was left that I could think of, too and we're really scraping bottom, it seems. Well, the cyl head thing is new and did not occur to me. We're all in suspense.
Similar threads
