Pesky little oil leak

[larrynimmo]

For months now I’ve been chasing down an oil leak….every flight I get a light film of oil on the front gear doors, but haven’t used a quart of oil in 9 hours….every chance I get, I’ve been removing the cowling and tightening up and looking for oil leaks (all with the supervision of my IA).  AIs point was it’s an airplane, you will have oil leaks… And every trip still yields oil.   Finally today I discovered oil on the oil temperature sensor…see pic…the only way I could photograph it (because of the odd access is with my borescope…)

then I removed it…gasket apparently didn’t crush correctly…

that sensor was installed when we installed the engine Lycomming factory rebuilt in sept 2018…so we went over 4 years before it stated to leak…
 

also, the oil did not appear to track down on the engine where the sensor is mounted 

hopefully I found the real culprit…as you can see my nose gear is well lubricate and will be forever rust free!

 

[David Lloyd]

I’ve owned 5 Lycomings, 4 Continentals. Every Lyco has leaked, some a little, some a lot.  Some have leak problems with Contis but each of mine were bone dry their entire lifetime.  Well, except for the stuck valve bending a pushrod which in turn broke a pushrod tube and made quite a mess.  Maybe Weep-no-more should do tanks and Lycomings.

[Guest]

6 hours ago, larrynimmo said:

For months now I’ve been chasing down an oil leak….every flight I get a light film of oil on the front gear doors, but haven’t used a quart of oil in 9 hours….every chance I get, I’ve been removing the cowling and tightening up and looking for oil leaks (all with the supervision of my IA).  AIs point was it’s an airplane, you will have oil leaks… And every trip still yields oil.   Finally today I discovered oil on the oil temperature sensor…see pic…the only way I could photograph it (because of the odd access is with my borescope…)

then I removed it…gasket apparently didn’t crush correctly…

that sensor was installed when we installed the engine Lycomming factory rebuilt in sept 2018…so we went over 4 years before it stated to leak…
 

also, the oil did not appear to track down on the engine where the sensor is mounted 

hopefully I found the real culprit…as you can see my nose gear is well lubricate and will be forever rust free!

 

That’s the wrong gasket.  The Rochester probe uses a solid copper gasket, search Spruce for it.

Clarence

[carusoam]

The gasket surely didn’t crush the right way…

Great pics Larry!

Proof that Lycomings don’t have to leak oil… they just have soooo many opportunities to leak oil…

Best regards,

-a-

[larrynimmo]

On 2/23/2022 at 8:26 PM, M20Doc said:

That’s the wrong gasket.  The Rochester probe uses a solid copper gasket, search Spruce for it.

Clarence

Very true….new sensor came with a solid stamped copper gasket…one difference, old sensor did not have a centering ridge for the gasket to sit in….new sensor had this ridge…as you tightened by hand til finger tight, you then have to shift the copper gasket over the brass ridge built onto the sensor…then torqued up.   No leak 

[kortopates]

x

[Guest]

12 hours ago, GEE-BEE AEROPRODUCTS said:

The gasket material that the oem will only last a few years until it oil soaks and cracks.

Gaskets have a shelf life.

We die cut ams3320 for Franklin engines and we have a lifetime warranty on the gaskets.

we stock three thickness based on drawings 

The oem will never revise the print , if they did they would not sell gaskets 

 

As much as I love some of your products, there are only a few in that picture that could be used safely.  Thin paper gaskets allow parts to be tightened and the fastener to reach proper torque.  A squishy silicone gasket under a magneto sounds like a really bad idea.  How many people here post about magnetos falling off due to poor installation technique?  Imagine adding the wrong gasket to the mix.

Clarence

[jetdriven]

How thick are your Lycoming VC gaskets? 

[larrynimmo]

On 2/26/2022 at 7:41 AM, M20Doc said:

As much as I love some of your products, there are only a few in that picture that could be used safely.  Thin paper gaskets allow parts to be tightened and the fastener to reach proper torque.  A squishy silicone gasket under a magneto sounds like a really bad idea.  How many people here post about magnetos falling off due to poor installation technique?  Imagine adding the wrong gasket to the mix.

Clarence

And let’s face it, the paper magneto gaskets don’t leak…and unlike other gaskets areas they have only two spots of compression, and is critically adjustable…paper gasket is the only solution for a mag

[Guest]

FAA PMA for any of these gaskets?  Spruce lists them all as “not FAA approved”. Why?

Most sane people wouldn’t and the FAA shouldn’t care about baffle seals which are without a doubt better than the originals.  

If silicone gaskets were better than paper for the rest, I’m sure Lycoming and Continental would have done it long ago.

Clarence

[Guest]

Interesting that this thread started with an oil leak caused by a certified but wrong gasket being installed on an engine. 

Clarence

[N201MKTurbo]

On 2/23/2022 at 12:24 PM, larrynimmo said:

For months now I’ve been chasing down an oil leak….every flight I get a light film of oil on the front gear doors, but haven’t used a quart of oil in 9 hours….every chance I get, I’ve been removing the cowling and tightening up and looking for oil leaks (all with the supervision of my IA).  AIs point was it’s an airplane, you will have oil leaks… And every trip still yields oil.   Finally today I discovered oil on the oil temperature sensor…see pic…the only way I could photograph it (because of the odd access is with my borescope…)

then I removed it…gasket apparently didn’t crush correctly…

that sensor was installed when we installed the engine Lycomming factory rebuilt in sept 2018…so we went over 4 years before it stated to leak…
 

also, the oil did not appear to track down on the engine where the sensor is mounted 

hopefully I found the real culprit…as you can see my nose gear is well lubricate and will be forever rust free!

 

 

 

Is your truss dented, or just chipped?

[larrynimmo]

3 hours ago, N201MKTurbo said:

Is your truss dented, or just chipped?

Both…it’s in that 1/32” range….

[N201MKTurbo]

36 minutes ago, larrynimmo said:

Both…it’s in that 1/32” range….

Be careful out there!

[larrynimmo]

8 hours ago, N201MKTurbo said:

Be careful out there!

Good advice….it was that way when I bought it approaching 5 years ago…I didn’t know better…whenever I leave the plane somewhere I “educate” the handlers for the best results

[N201MKTurbo]

54 minutes ago, larrynimmo said:

Good advice….it was that way when I bought it approaching 5 years ago…I didn’t know better…whenever I leave the plane somewhere I “educate” the handlers for the best results

Happens to the best of us....

[Josh1209]

Hello Larry, interestingly enough I'm having the same issue!  Was your issue handled with just the copper gasket or did you replace the entire sensor?

 

thanks, appreciate the help!

Josh

[larrynimmo]

14 minutes ago, Josh1209 said:

Hello Larry, interestingly enough I'm having the same issue!  Was your issue handled with just the copper gasket or did you replace the entire sensor?

 

thanks, appreciate the help!

Josh

With supervision of AI I replaced the sensor with a new stamped copper gasket…I didn’t take a pic of the new sensor, but it had a ridge allowing for perfect centering of the stamped copper gasket…the second picture shows a loosely fitting copper gasket

[Josh1209]

12 hours ago, larrynimmo said:

With supervision of AI I replaced the sensor with a new stamped copper gasket…I didn’t take a pic of the new sensor, but it had a ridge allowing for perfect centering of the stamped copper gasket…the second picture shows a loosely fitting copper gasket

Thanks for sending the pictures, I went ahead and ordered the sensor today.  I’ll let you know how it goes.