IO-360 Fuel Servo

[Cody Stallings]

I have been having some wondering EGT numbers for quiet sometime.

Looking in the Ram Air door lastnight I seen an alarming picture.

Im a Propeller Guy, Not a Powerplant Guy.

Im guessing those 4 little tubes are the 60’s version of a Mass Air Flow Sensor.

If that’s an Accurate observation, what would happen if that build up gets inside the tubes?

Edited December 14, 2017 by Cody Stallings

[tony]

do those cracks on the boot go all the way through?

[Cody Stallings]

  On 12/14/2017 at 12:14 AM, tony said:

do those cracks on the boot go all the way through?

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Yes.

we gonna get a new boot coming from Don on Monday.

The oil is coming from a pesky thrubolt leak!.

[Guest]

The impact tubes are part of the airflow measuring system for the servo and are meant to be clean.  It likely has something to do with your irratic EGT.

Clarence 

[N201MKTurbo]

I've cleaned them with brake parts cleaner (red) and it will get better for a while. You better start planning for an overhaul.

[Cody Stallings]

  On 12/14/2017 at 1:11 AM, N201MKTurbo said:

I've cleaned them with brake parts cleaner (red) and it will get better for a while. You better start planning for an overhaul.

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The break cleaner will not damage anything inside the Servo?

Also, where does it go after it settles?

[Dale Logsdon]

The impact tubes since the airflow into the engine ( like the pitot tube) and adjust the fuel pressure inside the servo. The tubes lead to one side of a diaphragm and that has no outlet. I would not think very much of the debris would get there since the air is static or almost. I would not use anything stronger than avgas to clean it if I were doing it.  

 

 

 

[Yetti]

Oil I get, where is the dirt that is mixing with the oil coming from?

 

 

[Cody Stallings]

  On 12/14/2017 at 2:59 AM, Yetti said:

Oil I get, where is the dirt that is mixing with the oil coming from?

 

 

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Best I can tell, from the split in the Boot.

[Jim F]

Hi Cody,

the oil must be from a little oil leak on the engine or how funny is this? A leak in the prop. Lol

the oil is getting in through the cracks and when the dust and dirt are sucked in the oils catching the dirt. I would replace the intake bellows.  Lycoming says something like a teaspoon of dirt is enough to cause wear that will need an overhaul. Make sure your ram air closes all the way with no leaks. The problem with EGTs wondering could be the servo but check the cheap stuff first. 

Do all EGTs rise at the same time? Only one cyl? Do you have engine monitor data?  Lean mag check data?  

Jim

[N201MKTurbo]

  On 12/14/2017 at 1:28 AM, Cody Stallings said:

The break cleaner will not damage anything inside the Servo?

Also, where does it go after it settles?

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Like others say, if you shoot solvent into the tubes it will get stuck inside the servo. You just want to wash it off a little. If you  put a rubber hose on one and gave it a little mouth pressure while you sprayed the rest you should be able to blow any that got inside out before it evaporates. 

The only good way to clean it is to disassemble it, which means overhaul.

Also try not to get any of the TCE in your mouth it is a bit carcinogenic. 

I doubt the brake cleaner will hurt anything in the servo, but washing a bunch of crud into it may.

[Cody Stallings]

  On 12/14/2017 at 5:29 AM, Jim F said:

Hi Cody,

the oil must be from a little oil leak on the engine or how funny is this? A leak in the prop. Lol

the oil is getting in through the cracks and when the dust and dirt are sucked in the oils catching the dirt. I would replace the intake bellows.  Lycoming says something like a teaspoon of dirt is enough to cause wear that will need an overhaul. Make sure your ram air closes all the way with no leaks. The problem with EGTs wondering could be the servo but check the cheap stuff first. 

Do all EGTs rise at the same time? Only one cyl? Do you have engine monitor data?  Lean mag check data?  

Jim

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Yes all egts float around about the same amount(EDM 700).

I have not downloaded the data though.

[tony]

  On 12/14/2017 at 12:22 AM, Cody Stallings said:

Yes.

we gonna get a new boot coming from Don on Monday.

The oil is coming from a pesky thrubolt leak!.

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So, I'm wondering if that would change the airflow sporadically and give you the issue you are experiencing.  I would fix that first the see what you have.