Oil leak mystery

[LANCECASPER]

50 minutes ago, Thomas661 said:

Carusoam,

Sorry I didn't see this reply until today. I am located in Carlsbad, NM, my plane is in Hobbs, NM an hour away from me, I fly to Tucson, AZ as much as possible because that is where my wife is currently living. I have found a mechanic in Arizona so I am in the process of finding the leak or why its burning oil. I still have an oil screen, so that needs to be changed out as well, and finding time to get this looked at is nearly impossible for me. I work in the gas and oil business and work 70-80 hours a week. trying to study for my IFR rating at the same time and then trying to get this issue resolved has been a daunting task!!! thanks for the advice though. Now that I have put about 100 hours on the engine since I have had it, It doesn't seem to leak as much as it did before but it does still leak some.

If you have a oil quick drain that's the first place I would look.

[Thomas661]

1 hour ago, LANCECASPER said:

If you have a oil quick drain that's the first place I would look.

I have removed and replaced with a new one already, couple weeks ago

[carusoam]

It helps to stay focussed...

Problem...

1) Oil is departing the engine at a higher than normal rate.

 

Evidence...

2) Pic shows oil on the nose wheel.  Is oil draining over time while the plane is unused?

3) oil leaves the engine in flight by the quart.

 

PP mechanical skills...

4) Got any ability to remove cowl parts and recognize oil drops?

5) Taking pics of things often helps, post them...

5a) There are several rubber hoses and hardware that can be identified if leaking or not... or loose or not...

5b) case cracks are tough to identify, but not out of the realm if you have worked with an engine before...

5c) Got a maintenance manual for the O360? Are you good with manuals?

 

Mechanic skills...

6) The O360 is one of the most common engines in GA...

7) The Oil leak is engine related.

8) Good news, any mechanic can help identify the problem... 

9) No Mooney experience required to find the leak...

10) Oil screens are a normal oil cleaning device... sure a filter would be better... an ordinary screen won’t be causing the oil leak...

 

Staying focussed...

11) Use Dr. Seuss’ process of elimination....  it is that basic. (No music required) 

12) write a list of possibilities where oil can leak...

13) Check each place to see if it leaks or not...

14) it may help to clean the engine first... it may be coated in quarts of oil...

15) There are high probability and low probability oil leaks... organize your list...

16) Some things take less than an hour to accomplish... organize your list again...

17) Some things are less critical than others... organize your list again...

18) If you get an hour with the plane... what are you going to attack first?

PP thoughts... 

19) Flying a plane with an unknown leak won’t fix itself.

20) there are few stable oil leaks... most get worse without any notice.

21) if you insist on flying the plane...

22) and you don’t have a mechanic on your field...

23) and your own mechanical skills aren’t where they need to be(?)

24) Consider flying the plane to a mechanic...

25) Consider flying a mechanic to the plane... (some actually drive with a truck full of tools)

26) Consider not flying the plane until the oil leak is found...

 

Notes on work...

27) we have a few people in the oil business around here...

28) Some travel internationally by the month...

29) When you work that many hours in a week... everything gets hectic...

30) The right job... gets paid for the extra hours...

31) The extra right, super job, gets paid time and a half for all hours above 40... 

32) Being a contract employee... no benefits... but time and a half for a couple of years can really help with the bills...

33) I met a new Ovation owner at KOSH this year... he was in the oil business too...! 

 

These are a list of private pilot thoughts... I am not a mechanic... the most hours in a week I worked was just over 100...

Take care and Best regards,

-a-

[Ragsf15e]

You need to be pretty anal about when you check the oil to give yourself a means of comparison.  If you come out to the airplane and it hasn’t flown in a week, that’s a reasonable place to check the oil for comparison.  Say you fill it to 6, then fly it fir an hour.  Check it immediately after landing and it will be at 5.  This is not a valid time to say I burn 1 qt/ hour.  Check it 48 hours later and it will be 5.5.  Still not valid.  Check it in a week and you might be right back at 6 or pretty close.  It really drains down that slowly.

Also, what type of cylinders do you have?  Chrome uses more oil.  Noticeably more.

[Prior owner]

On ‎12‎/‎7‎/‎2019 at 7:52 PM, Ragsf15e said:

Also, what type of cylinders do you have?  Chrome uses more oil.  Noticeably more.

True that!

[Greg@williamslawoffice.us]

I recently had the same problem with my M20K/262.  We traced the oil leak to the vacuum pump and replaced the garlock seal behind it.  However, that did not resolve the problem.  Apparently there is a T-drive adapter which attaches to the engine accessory case and drives the vacuum pump.  On my plane it also has a second alternator bolted to it which is belt driven.  There as a blank plate on the T-drive adapter which has a second garlock seal inside of it.  That seal had failed, allowing oil to cumulate inside the blank plate during flight, and on shutdown that oil then would migrate along the drive adapter for the vacuum pump and out of the engine.  It also dripped directly onto the automatic waste gate which made it look like that was the site of the leak.

So, it was a $10 seal to replace, just a few AMU's to find the problem.

[tmo]

12 hours ago, Greg@williamslawoffice.us said:

So, it was a $10 seal to replace, just a few AMU's to find the problem.

But thanks to you sharing the info and the power of MooneySpace one of our comrades might end up finding it on the first attempt. Thank you!

[flyingchump]

I have successfully (and cheaply) chased down 3 oil leaks in the past 3 months.  I would HIGHLY recommend that anyone chasing an oil leak buy a cheapo bore scope.  We all know how tight our engine compartments are.  There are places you just can't see with flashlights, mirrors, and contortion.  

I almost overhauled my governor because it was covered with oil and leaking to the ground.  After closer inspection with the borescope, it was not the governor at all.  It was the gasket for the oil filter accessary housing.  The gasket was jest leaking on the governor.  Its much cheaper to find the real problem before starting to overhaul stuff. 

https://www.amazon.com/gp/product/B01MYTHWK4/ref=ppx_yo_dt_b_asin_title_o08_s00?ie=UTF8&psc=1

 

Edited November 30, 2020 by flyingchump

[Rjfanjet]

I just replaced all of the oil return lines. The clamps weren’t working anymore.

[carusoam]

Holy original looking hardware, bat man!  

See if new hardware direct from Lycoming still looks the same..?

My M20C got new hoses and clamps of ordinary looking hose clamps, just tiny...

PP thoughts only, not a mechanic...

Best regards,

-a-

[Mad Mikey]

Had the EXACT thing happen to my M201 1979. FINALLY tracked it down to the seal on the rear of the engine that drives the gear for the vacuum pump. Changed seal, very inexpensive 13.00, plus labor.  Solved problem immediately. It was such a relief after many months and hours of trying to trace the leak.  Might want to check that.  Safe flying !!!!