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  #1  
Old 03-28-2018, 09:25 PM
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Phantom30 Phantom30 is offline
 
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Default Checking Oil Level

Love to hear a concenses on this....maybe Jolly will jump in.

Oil change as per manual...however, when I check oil level (cold), it is halfway up the stick (middle of recessed part). After getting plane to 120+ (shutting down), propping 20+ times...the oil level is 1/2+ above full mark (you can see oil almost to top plate.

Oil change was done with cold engine....propped around 15 turns. Im wondering if engine oil should be hot when changed I.e. because maybe not all oil is transferred to tank (with new tight engine maybe blow by {oil cold} is hard to move oil.

???????
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  #2  
Old 03-28-2018, 11:03 PM
Jolly Jolly is offline
 
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Default

Hi Ric,
If it's just a tad fuller than what you expected then it isn't a big deal unless it's so full up in the neck it may overflow out the vent tube and that just makes a big mess to clean up, but doesn't hurt anything.
When you do an oil change the engine should be gurgled first whether it is hot or cold. Warm oil does flow better. Then whatever oil is hanging out in the bottom of the crankcase will go back to the tank before you drain it. If you don't do this gurgle first you may end up with an over filled oil tank when you put your 3 liters back in. It won't hurt anything just make a big mess if it's full enough to over flow out the vent tube. Normally if the normal amount of oil gets drained then adding back the 3 liters of oil usually puts it around the top of the flat area on the stick.
Gurgling the engine is not an exact measure all the time of the exact oil level. It can lie to you. You are looking for a safe level of oil and not always the exact amount. Sometimes it's pretty accurate and maybe sometimes it shows a tad lower than what you may expect. The prop rotation before flight also checks for any oil that may have seeped into a cylinder and then you'd get hydro-lock when you turned the key which will bend things.
The new oil filter 825-016 does not have the internal check valve that the last one did 825-012. These new filters can now be pre-filled.
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  #3  
Old 03-28-2018, 11:55 PM
Driftdown Driftdown is offline
 
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Location: Clearwater, Florida
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Quote:
Originally Posted by Phantom30 View Post
Love to hear a concenses on this....

Oil change as per manual...

Oil change was done with cold engine....
Which "manual" are you referring to?
Did you follow the oil change instructions in the Rotax Line Maintenance Manual?
Changing the oil with a cold engine is contrary to those instructions.
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  #4  
Old 03-29-2018, 12:28 AM
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Phantom30 Phantom30 is offline
 
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Quote:
Originally Posted by Driftdown View Post
Which "manual" are you referring to?
Did you follow the oil change instructions in the Rotax Line Maintenance Manual?
Changing the oil with a cold engine is contrary to those instructions.
I kinda figured “cold” engine to be root cause....normally not a problem; however, due to repaving of area in front of hangar. Not able to fire up engine.

Live and learn��
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Ric Dickison
307 (CAB) Phantom
Search and Destroy (Can
Tho RVN)
Distinguished Flying Cross Society Member
CH-47 & UH-1H "Driver"
Rotax 9 Series Service IRMT

RV-12 Kit#729 "N312RD" is now a full functioning fun machine!! Thanks Van for fulfilling my dream😎
2018 Dues Paid

Last edited by Phantom30 : 03-29-2018 at 09:21 AM.
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  #5  
Old 03-29-2018, 05:10 AM
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Piper J3 Piper J3 is offline
 
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Cold oil change is never a good idea. Best to change when oil is warmed up and particles stirred into suspension so they drain with the oil...
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PPL/ASEL 1970 - Sport Pilot since 2004
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  #6  
Old 03-29-2018, 07:15 AM
Bad1996 Bad1996 is offline
 
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Right, the main reason for warm/hot oil is to suspend the particles....get the trash up and moving in the oil. Yea, it drains easier too if colder temps.
I feel your pain though. It was hard for me to do an oil change and not overfill. Now I'm satisfied with the oil being below the full level on the first flight.
After the tank drains out I will still pull the prop thru and that usually gets some more oil to drain.
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  #7  
Old 03-29-2018, 07:35 AM
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Piper J3 Piper J3 is offline
 
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Quote:
Originally Posted by Bad1996 View Post
Right, the main reason for warm/hot oil is to suspend the particles....get the trash up and moving in the oil. Yea, it drains easier too if colder temps.
I feel your pain though. It was hard for me to do an oil change and not overfill. Now I'm satisfied with the oil being below the full level on the first flight.
After the tank drains out I will still pull the prop thru and that usually gets some more oil to drain.
Best not to burp engine with oil tank drained. You will suck air into the oil pump which can cause problems with hydraulic lifters. Burb engine prior to draining oil tank, change filter, refill the tank with 3 liters, and fly.
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Jim Stricker
Hinckley, Ohio
EAA #499867
PPL/ASEL 1970 - Sport Pilot since 2004
80 hrs Flying Aeronca Chief 11AC
1130 hrs Flying 46 Piper J-3 Cub
RV-12 E-LSA #120058 AWC Jul 2012 - Bought Flying Oct 2015 with 48TT - Hobbs now 400

LSRM-A Certificate 2016
Special Thanks to EJ Trucks
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  #8  
Old 03-29-2018, 08:52 AM
rvbuilder2002 rvbuilder2002 is offline
 
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Quote:
Originally Posted by Piper J3 View Post
Best not to burp engine with oil tank drained. You will suck air into the oil pump which can cause problems with hydraulic lifters. Burb engine prior to draining oil tank, change filter, refill the tank with 3 liters, and fly.
Correct

Turning the prop with an empty tank probably warrants doing a purge procedure of the system before starting.

A common cause of over filling is when the oil level is checked at colder temps, found to be low, and more oil added.
If there is much oil laying in the bottom of the crank case, even if you burp the engine before checking, there will still be quite a bit of oil coating the interior bottom of the crank case and because of the cold temp it is slow to migrate to the return fitting on the bottom of the engine case.
Once the oil is hot and much lower in viscosity, it can quickly migrate to the outlet and get pushed back to the tank. Checking the oil level when it is hot will always be more accurate.
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  #9  
Old 03-29-2018, 12:25 PM
Driftdown Driftdown is offline
 
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Quote:
Originally Posted by Piper J3 View Post
. . . . . Burb engine prior to draining oil tank, change filter, refill the tank with 3 liters, and fly.
As per the Rotax Line Maintenance Manual, before actually starting engine, the prop should be turned 20 revolutions.
For 3-blade props, that's means pulling through 60 blades.
For 2-blade props, that's means pulling through 40 blades.
That ensures the oil filter has been filled with oil (displaces air) and it immediately initiates lubrication to the engine during the start.
Very important to eliminate any air in lines and filter, otherwise an oil purge should be done.
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  #10  
Old 03-29-2018, 02:36 PM
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Piper J3 Piper J3 is offline
 
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Quote:
Originally Posted by Driftdown View Post
As per the Rotax Line Maintenance Manual, before actually starting engine, the prop should be turned 20 revolutions. That ensures the oil filter has been filled with oil (displaces air) and it immediately initiates lubrication to the engine during the start.
Very important to eliminate any air in lines and filter, otherwise an oil purge should be done.
I've been thinking about this and I understand wanting to fill the filter to get oil pressure on first start-up, but where does the displaced air from the filter go? It has to go into the oil galleries of the engine - it can't go anywhere else. Maybe 20 turns is enough to purge the air out through the main bearings...
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Jim Stricker
Hinckley, Ohio
EAA #499867
PPL/ASEL 1970 - Sport Pilot since 2004
80 hrs Flying Aeronca Chief 11AC
1130 hrs Flying 46 Piper J-3 Cub
RV-12 E-LSA #120058 AWC Jul 2012 - Bought Flying Oct 2015 with 48TT - Hobbs now 400

LSRM-A Certificate 2016
Special Thanks to EJ Trucks

Last edited by Piper J3 : 03-29-2018 at 02:39 PM.
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