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Fuel oil mix dripping


MooneyBob

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Attached is the picture of what is collected after few flights in my oil dripping pan. 

Part of it is regular oil from the breather but the blue/green stuff that looks and feels like gas and oil mix comes from the hose that is connected to the bottom of the crankcase.

Any ideas? Thanks 

381B01B7-BC76-45B6-B115-ACE7CAF2F79C.jpeg

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Hi Bob,

The 1/4 inch hose out of the bottom of the sump is a intake drain. The fuel inside after priming of on shutdown will drain out normally. 

You should verify what hose and where is goes. Could be fuel from the intake and oil from the fuel pump oil seal drain. 

Also we need engine model, time, any other problems?

Jim F

 

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10 minutes ago, Jim F said:

Hi Bob,

The 1/4 inch hose out of the bottom of the sump is a intake drain. The fuel inside after priming of on shutdown will drain out normally. 

You should verify what hose and where is goes. Could be fuel from the intake and oil from the fuel pump oil seal drain. 

Also we need engine model, time, any other problems?

Jim F

 

Jim, 

thanks for the response. Yes, it is the hose from the intake drain. Every time I check it it has a drop of fuel ( or oil fuel mix) on the end. 

The other hose coming from the fuel pump is dry. No sign of any liquid coming from it.

The breather tube has drop of oil on its end too but I consider it normal. 

IO 360 A3B6

90hrs after OH. No other problems except higher level of chromium in the oil analysis report after OH. 

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Hi Bob,

What is your oil consumption?  Bad mag check?  Does the the engine shutoff when you go to ICO?

The oil could be coming from a intake guide. 

I would clean the tray each time and take pictures of the puddle. 

You might call the shop that did the OH and ask them to look at it. 

Jim F

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Bob,

There are two sources of drips to expect...

1) Fuel injector system...   are you familiar with the sniffle valve?

It a simple check valve on a drain with a plastic ball in it.  It suffers from a lot evaporation concentration issues.  May need some cleaning...

Search for Sniffle Valve...

2) The oil probably comes from the Case vent.  Put in more than seven quarts and it drains/blows out the excess...

 

 

You should be able to trace the hoses back to their origin.

 

PP thoughts from NJ, not a mechanic...

Best regards,

-a-

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19 minutes ago, Jim F said:

Hi Bob,

What is your oil consumption?  Bad mag check?  Does the the engine shutoff when you go to ICO?

The oil could be coming from a intake guide. 

I would clean the tray each time and take pictures of the puddle. 

You might call the shop that did the OH and ask them to look at it. 

Jim F

Normal oil consumption.

Engine cuts off normally in idle and mixture cut off

I will have mechanic to look at it. Thanks 

 

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26 minutes ago, carusoam said:

Bob,

There are two sources of drips to expect...

1) Fuel injector system...   are you familiar with the sniffle valve?

It a simple check valve on a drain with a plastic ball in it.  It suffers from a lot evaporation concentration issues.  May need some cleaning...

Search for Sniffle Valve...

2) The oil probably comes from the Case vent.  Put in more than seven quarts and it drains/blows out the excess...

 

 

You should be able to trace the hoses back to their origin.

 

PP thoughts from NJ, not a mechanic...

Best regards,

-a-

I didn’t even know there is the sniffle valve. Yes, the fuel comes from the hose connected to the location where the valve would be. Good point, A. I’ll check with my mechanic. Thanks. 

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Attached is the picture of what is collected after few flights in my oil dripping pan. 
Part of it is regular oil from the breather but the blue/green stuff that looks and feels like gas and oil mix comes from the hose that is connected to the bottom of the crankcase.
Any ideas? Thanks 
381B01B7-BC76-45B6-B115-ACE7CAF2F79C.thumb.jpeg.22d6914afac21676f19c522dfa332878.jpeg


Looks normal to me. I have seen this for the past 26 years. I put cat litter in my pan to catch and hold it. You can kind of see it in the picture.

e6a2d8c661d2af7626b0f1f9a5614f8e.jpg


Sent from my iPad using Tapatalk Pro
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On ‎11‎/‎28‎/‎2017 at 8:04 PM, MooneyBob said:

Jim, 

thanks for the response. Yes, it is the hose from the intake drain. Every time I check it it has a drop of fuel ( or oil fuel mix) on the end. 

The other hose coming from the fuel pump is dry. No sign of any liquid coming from it.

The breather tube has drop of oil on its end too but I consider it normal. 

IO 360 A3B6

90hrs after OH. No other problems except higher level of chromium in the oil analysis report after OH. 

I think you would expect to see some fuel draining from the intake manifold after a normal shutdown.  IIRC, Don Maxwell (in his hot start video) commented that after shutdown, the fuel in the divider heats up and pushes the fuel in the lines into the intake over the first couple minutes.

If there was a stuck sniffle valve, I assume then you would have NO fuel dripping?

The cat litter idea is good, but it does make it hard to see if there is a change in what is dripping on the floor.

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