Possible cracked oil drain tube...

[BRBENNETT]

Mooney M20F, Lycoming IO360-A1A

I ran across this on a routine oil change.  See pictures.  it appears the oil drain tube has a hole or is cracked on cyl#4.  I am also noticing some oil  on the #2 cylinder intake tube and on the side cowling panel.  I am thinking the oil from #4 could be "blowing" around in the cowling and just sticking on #2 and the panel.

Anyone ever seen this happen?  I can't confirm until I remove the tube that this is the issue.  Weird that it almost looks like fuel due to the blueish color.

Any comments are welcome!!

 

[RLCarter]

Looks like the intake runner is leaking as well 

[takair]

That looks blue.  There looks to be a drip up higher.  You sure it is not the injector leaking?  There does appear to be some damage to the oil return line too, but It is hard to tell without cleanup.

[Ragsf15e]

I don’t doubt there’s a little oil there too, but that’s fuel.  Maybe it shouldn’t, but my F looks about the same.  Either the injectors are dribbling a bit (is the tiny air hole pointing up?) or the intake tube gasket is leaking a little.  The airflow under there is crazy, so it might be from either cylinder and either place.  Honestly, that doesn’t look terrible....

[47U]

Nice catch.  Being observant and catching these visual clues for further investigation, before they become major problems, can save you time, money, and perhaps a catastrophic loss of engine power.

[carusoam]

Intake valves are lubricated by the oil that line takes away...  if you have an O360... their is decades of blue goo deposited in the area... as the fuel evaporates in their air intake tubes...  fuel injectors do a much better job at sending the blue dye into the cylinder...

1) What rubbed the hole in the line?  There  are a few deep scratches that may have lead to the crack...

2) invite @M20Doc  to have a look... blue dye appears to be exiting a cut in the oil return line from the valves of a cylinder on an IO360...

3) find the nearest fuel injector... inspect for blue dye escaping the vent hole... it’s possible the FI didn’t get aligned properly allowing for the leak... (common issue for FIs)

It looks like two separate leaks occurring in the neighborhood... but there is oil in the area of the blue dye... the oil has a big dry drip on the oil line...

PP thoughts only, not a mechanic...

Best regards,

-a-

[Guest]

The oil line doesn’t look good and should be replaced before it breaks.  Did you wipe up any oil from it?  The blue stain on the intake tube is from a fuel leak.

Clarence

[N201MKTurbo]

When the drain line gets a hole in it, you get a very messy engine. It will seep and drip for hours after shut down. I don’t see any of that. It is probably the injector directly above it, up chucking a little fuel through its air bleed. Some do that some times. It is a bit of a mystery as to why.

Edited March 12, 2021 by N201MKTurbo

[BRBENNETT]

Thanks to all for your comments.  Just as everyone thought, the blue is fuel dripping from the nozzle above. In fact...all of the nozzles have a bit of blue around them.  I have noticed this over the years.   This sounds a bit normal according to your comments.  I'll keep an eye on it for now and check it more often to if the condition is stable or is getting worse.

[BRBENNETT]

I found this old thread... I recently had an annual where they removed and cleaned the injector nozzles.  I got a feeling the weep hole is located in a different position and thus this is why I am seeing the blue deposit in a place I didn't see it before.

https://mooneyspace.com/topic/10383-leaking-fuel-injectors/

 

 

thanks again to everyone helping me understand the issue!!

 

[carusoam]

10 hours ago, BRBENNETT said:

I found this old thread... I recently had an annual where they removed and cleaned the injector nozzles.  I got a feeling the weep hole is located in a different position and thus this is why I am seeing the blue deposit in a place I didn't see it before.

https://mooneyspace.com/topic/10383-leaking-fuel-injectors/

 

 

thanks again to everyone helping me understand the issue!!

 

This is an orientation of the fuel injector symptom...

They have a letter on the nozzle that gets oriented to a particular direction... 

There is a procedure for that...

Probably around here somewhere... I remember the drawing of an A on the FI and an arrow pointing toward the right direction... 

It is not normal for them to behave this way...

Continue to find the proper solution...

Fuel dripping anywhere under the cowl is bad...

Even oil leaks have been figured out...

Fuel and oil leaks under the cowl can be stopped...

Some of the maintenance can be pretty low cost...

Unlike radial engines... Mooneys don’t mark their territory...  

PP thoughts only, not a mechanic...

Best regards,

-a-

[Ragsf15e]

Yes, but if I remember right, the letter points down... like where you can’t see it.  So it’s really hard (or impossible) to see if you’ve done it right.  My mechanic put a line with a sharpie on the side opposite the letter and pointed that up.  I swear they still burble out a little.

[Guest]

On 3/13/2021 at 6:44 AM, BRBENNETT said:

I found this old thread... I recently had an annual where they removed and cleaned the injector nozzles.  I got a feeling the weep hole is located in a different position and thus this is why I am seeing the blue deposit in a place I didn't see it before.

https://mooneyspace.com/topic/10383-leaking-fuel-injectors/

 

 

thanks again to everyone helping me understand the issue!!

 

Look up Lycoming S/I 1275C, it covers cleaning and installing your fuel nozzles.

Clarence