Faint oil spray on cowl near spinner

[Marvin]

I noticed some faint streaking on the windscreen prior to my last flight of 12 minutes.  After putting the airplane away, I performed a wipe down and noticed a very faint dark speckling around the spinner on the engine cowl.  Oil level is holding steady and no other obvious leaks.  Last oil change was ~23 hours ago.  Any ideas?  

To see the spray pattern, you have to zoom in.  

[neilpilot]

If this continues, it maybe the prop crankshaft seal.  Typically an easy repair but the prop need to come off.  The seal leak can put a significant oil mist on the cowl and windscreen with minimal oil loss.

Edited July 28, 2021 by neilpilot
Said “prop seal” but meant crankshaft seal

[carusoam]

Welcome aboard Marvin…

tragic first post… 

props have the tendency to leak oil or grease…

Stand by for some additional ideas…

I’ll invite @Cody Stallings our prop guy stop by…

Best regards,

-a-

[kortopates]

i can’t zoom in but if the propeller face is dry it’s more likely to be your crankshaft seal - even easier to fix.


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[louisut]

We've had this issue on and off. A&P and prop shop have said that a little oil is not a big deal, and to try cycling the prop fully on the ground a couple times to reseat the seal. If it continues to leak heavily, then it may be time to replace the seal.

[OR75]

oil mist ..... probably getting close to prop overhaul or reseal time 

[Marvin]

Thanks all.  It looks like a prop overhaul is in the offing.  It has been 15 years since the last one.  Still has over 800 hours left but especially with the leaking seal it is safe say it is long overdue. 

[Cody Stallings]

Hard to say where that is coming from.

If it is coming from the propeller, Just be advised that the O/H is the least cost effective way to Fix it.

[75_M20F]

On 7/28/2021 at 9:28 PM, Cody Stallings said:

Hard to say where that is coming from.

If it is coming from the propeller, Just be advised that the O/H is the least cost effective way to Fix it.

Similar issue with my prop which was last overhauled in 2007. I think it is about time for an overhaul or IRAN on it. What is the turn around time for this at your shop?

Thanks!

 

[Schllc]

I had some intermittent streaking on the windshield of my acclaim over the last few months. Faint, not every flight.  I thought it may be the prop as well, had that looked at and it checked out. 
Today, after a 4 hour flight Thursday and a 3+ hour return flight today, the prop governor housing cracked and I lost about four quarts of oil. 
Best I can tell, it happened after power change on final approach. I never saw elevated temps, or loss of oil pressure and the data log confirmed. 
It looked like someone pressure washed the bottom of the plane with oil.  
I was fortunate for it to fail when it did. I would have the prop and governor checked thoroughly. 
I wish I took pics before I cleaned, but I was so freaked out on landing I wanted to get the plane in the hangar and the cowling off before it all dropped off the engine. 

[carusoam]

Yikes!

not too late to get a good pic…
 

Pics of all the oil would be noteworthy…

Pics of the crack in the governor housing would be worth a million notes..! 

 

That is something we would like to share with our prop guy and the doc…  @Cody Stallings and @M20Doc

 

Best regards,

-a-

 

[Cody Stallings]

2 hours ago, 75_M20F said:

Similar issue with my prop which was last overhauled in 2007. I think it is about time for an overhaul or IRAN on it. What is the turn around time for this at your shop?

Thanks!

 

We could reseal or IRAN that propeller in about 3-4 days this time of season

[jaylw314]

On 7/28/2021 at 12:24 PM, Marvin said:

Thanks all.  It looks like a prop overhaul is in the offing.  It has been 15 years since the last one.  Still has over 800 hours left but especially with the leaking seal it is safe say it is long overdue. 

Just send it out for an IRAN and ask if it can be repaired/resealed.  Worst case scenario, you need a new prop ($10K).  Middle-case scenario, needs an overhaul.  Best case scenario, just needs some reseal work ($1-2K?).  Major difference in money.  Unless there's another reason, there's no reason to overhaul the prop just for leak.

[Schllc]

[Browncbr1]

I am in the middle of replacing the crank seal on my 1100hr engine.  I’m not sure if the split type seal is workable with the J spinner and starter ring or not.   On mine, the prop has to come off, so I’m using the one piece stretch type seal.     
 

at first I thought it was the prop leaking too

[Yetti]

lots of different planes in this thread.  What grease is in your hub?  if Aeroshield 6 you may want to switch to 5.  To check the prop seal put your finger on it and move the prop.  If it spins with the prop.  It is time.

 

Edited August 21, 2021 by Yetti

[carusoam]

@M20Doc have you seen an Acclaim’s govenor leak oil through a crack before?

See sch’s pic and details above…

Best regards,

-a-

[KSMooniac]

I'm not sure what plane is involved with the OP, but I had a similar leak on my J and it turned out to be the elbow fitting on the hard governor oil line going to the front of the engine. That was hard to determine! Tiny crack in the fitting that let the high pressure oil spray a fine mist into the incoming air, making it difficult to find a source.

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