Breather Tube position on O-360

[Janat83]

Hello Mooniacs 

I'm concerned about oil streaks on my left inner walls of my engine cowling, I see oil coming from the breather tube and probably that little hole in that tube. 

I have attached some pictures for you to give your opinion or to share how your breather tube is positioned. 

Best Regards 

Moustafa Janat 

Edited March 16, 2023 by Janat83

[hammdo]

The whole is in case the opening is frozen.

I’m able to keep her ‘mostly’ clean but oil finds a way it seems… Mines routed the same way…

-Don

[Vance Harral]

Having operated an aging engine with an assortment of minor oil leaks for years, I'll opine two things:

1. The amount of oil you're seeing is not even remotely close to a safety concern, though I appreciate that it's annoying, and it would be nice to know where it's coming from.
2. In an airplane that actually gets flown, there is very little correlation between where oil is leaking from, and where it winds up inside the cowl.

If you really want to know where an oil leak is coming from, you have completely and meticulously wash the engine with a degreaser, then try one of the tricks that identifies leak spots: foot powder, talc, UV dye in the oil, etc.  I'm not saying it's not coming from the breather tube and the "whistle slot" hole that's intended to keep it from freezing shut.  But the fact that tube is in the vicinity of the drips on your cowl cheek panel isn't very strong evidence for that particular hypothesis.

[47U]

1 hour ago, Janat83 said:

I'm concerned about oil streaks on my right inner walls of my engine cowling,

MJ,  I’m spatially disoriented… sorry.  You meant left inner walls, no?  

Vance (above) is right on… but check those easy things on #2 and #4 cylinders… rocker box gaskets, pushrod tube seals, rocker box oil drain back tubes… is the lower-center cowling dry?  The oil is only accumulating on the inner cowling wall?

Please, keep us updated.

[MikeOH]

Yeah, that's pretty minor.  I've had both rocker cover gaskets and the oil drain back tubes be sources.

The real question is did you just notice this, or is it demonstrably WORSE than what you've seen before?

[Janat83]

13 minutes ago, 47U said:

MJ,  I’m spatially disoriented… sorry.  You meant left inner walls, no?  

Vance (above) is right on… but check those easy things on #2 and #4 cylinders… rocker box gaskets, pushrod tube seals, rocker box oil drain back tubes… is the lower-center cowling dry?  The oil is only accumulating on the inner cowling wall?

Please, keep us updated.

Yes left side (pilot side), I have corrected my post, my mechanic said he will look at this next annual in April but I wanted to know if someone have some thoughts that might be helpful, thanks again

[Janat83]

8 hours ago, MikeOH said:

Yeah, that's pretty minor.  I've had both rocker cover gaskets and the oil drain back tubes be sources.

The real question is did you just notice this, or is it demonstrably WORSE than what you've seen before?

It's been there since few months, was able to locate other source and fixed it but now I think it's related to the breather tube position 

[MikeOH]

4 hours ago, Janat83 said:

It's been there since few months, was able to locate other source and fixed it but now I think it's related to the breather tube position 

Do you have reason to believe the breather tube position has changed? If it hasn’t moved then it seems unlikely to be the source….unless it’s always been leaking a little. That is, nothing new.

While it’s great to notice little things that may portend problems, just be careful not to get too neurotic chasing stuff!