Help locating my Oil Leak (photos) or is it normal?

[N601RX]

Is the injector oriented correctly? The marking should be down and the hole up.

[Guest]

Drew,

The AD in question is AD2011-26-04 which drives you to complying with Lycoming SB 342G, inspection of the fuel lines and clamps. If you remove your fuel nozzles for cleaning, reference Lycoming SI 1275C.

In looking at the pictures, the rocker gasket for cylinder 2 appears to be displaced from between the cover and the cylinder head. Quite common with silicon gaskets when they are installed wet, and then over torqued. A possible source for the oil leaks?

Clarence

[carusoam]

so...

How even are the EGTs compared to the leaking fuel/intake...

I would expect that the cylinder may demonstrate an air leak entering when the blue fluid is no longer exiting...

does that cylinder peak first?

It is a clear sign of the intake asking for maintenance. Not a very complex job. check to see if there are two bolts holding the top collar in place...?

Can you smell the 100LL at start up or shutdown?

Things that come to mind when I see blue exiting the air intake tubes...

If you had a carburetor at the bottom of the intake tubes, the blue goo exiting would be much thicker and darker....

best regards,

-a-

[Ragsf15e]

Update - Got the top cowl off and can clearly see the fuel leaks at the injector on #2 and #3... and smaller leaks at #1 and #4.  Yep, all 4 injectors were leaking where they screw into the cylinders.  My AP is taking them out, cleaning them and reinstalling them.  He said they are supposed to be installed without any sealant and it's not uncommon for them to leak.  Lesson learned.  We're also replacing the gasket on the air intake (#2) since that appeared to have its own leak, but it was hard to tell with all the fuel dribbling down from the injector.

 

I'm not really thrilled with fuel dribbling over my hot engine... how much do you think it would take to catch fire?

 

Also, to answer the above post... I checked the data from my EDM 930 and yes, the #2 and #3 cylinders were peaking first when I leaned for cruise.  I remember them all peaking about the same time when I first got the airplane, so that could have been a symptom, although it wasn't much.

 

Drew

[FloridaMan]

I think GAMIs always sweat a little, but that looks excessive. All of my cylinders have dark discoloration around the GAMIs. 

 

Is your #2 EGT peaking before the others? I'd be suspicious of a partially clogged injector or perhaps a crack in the fuel line from the spider. With the engine off, I'd open the throttle, full rich and run the boost pump with the cowling off and see if I could see where that fuel was leaking from. Your engine will eventually start draining fuel out from a drain line under the belly after running the pump for several seconds (With the engine off, fuel ends up draining into the intake and then out the drain in the intake manifold), one cylinder will be loaded up with fuel (the one with the intake valve open fills up) and it may be a little weird starting. 

[Bob_Belville]

I'm thinking you may look under the hood now and then for a while at least. 

[Ragsf15e]

Yep! 

[Marauder]

Update - Got the top cowl off and can clearly see the fuel leaks at the injector on #2 and #3... and smaller leaks at #1 and #4. Yep, all 4 injectors were leaking where they screw into the cylinders. My AP is taking them out, cleaning them and reinstalling them. He said they are supposed to be installed without any sealant and it's not uncommon for them to leak. Lesson learned. We're also replacing the gasket on the air intake (#2) since that appeared to have its own leak, but it was hard to tell with all the fuel dribbling down from the injector.

I'm not really thrilled with fuel dribbling over my hot engine... how much do you think it would take to catch fire?

Also, to answer the above post... I checked the data from my EDM 930 and yes, the #2 and #3 cylinders were peaking first when I leaned for cruise. I remember them all peaking about the same time when I first got the airplane, so that could have been a symptom, although it wasn't much.

Drew

Seeing a little blue around the injector may be okay, but you had much more than that to get what is shown in the pictures.

There is no sealant on the injectors, but there is a torque setting for the injectors and I think one for the injector tubes as well.

[Stefanovm]

Mine gets about 4 to 6 hours per quart. There is very little gone from a stick reading when my left side, not underneath particularily, is speckled with oil. Each year of the last 5 the IA attacks something different. Last year was the valve cover gaskets going to silicone as they required tightening to the 20 inch punds on a regular basis. The year before some hoses, etc. I have taken the time to look for the cause myself using the methods suggested. It seems to be coming from the push rod tubes on the pilot side front cylinder. There is no visible oil with cowling off from any other locations. It is more of a job than I can do and my mechanc who knows a lot about Mooneys says "probably not" after inspecting. The leak continues and bothers line workers.

[712Walt]

I've put about 1800 hours on my '83 201. Most of the hours on a daily commute. My experience is that the Lycoming 360's spit out anything more than 6 1/2 quarts. The FAA requires that the design functions properly with only 4 quarts. If the belly is oily and you can't find any gasket leaks the oil is coming out the breather tube. Lower oil level flying can result in higher oil temperatures with prolonged climbs and high ambiant temperatures.

[Ragsf15e]

Walt - I definitely agree with you, now if I could just get my A&P to only put 6 quarts in on an oil change!  I know I should keep it between 6 and 8 quarts, but I generally don't put any in until i hit 5.5 and then i only fill it up to 6.  Staying between 5.5 and 6 keeps the belly clean and decreases the oil use for me.

 

I'd love to hear if others let theirs go slightly below 6 before they put oil in?

[Marauder]

Walt - I definitely agree with you, now if I could just get my A&P to only put 6 quarts in on an oil change! I know I should keep it between 6 and 8 quarts, but I generally don't put any in until i hit 5.5 and then i only fill it up to 6. Staying between 5.5 and 6 keeps the belly clean and decreases the oil use for me.

I'd love to hear if others let theirs go slightly below 6 before they put oil in?

All the time unless I am doing a flight longer than a couple of hours.

[Marauder]

I should add that I won't let it go below 5.

[Ragsf15e]

Good to hear I'm not alone.  Knowing my oil usage, I'm comfortable to takeoff on a 3-4 hour flight with 6 qts.  When I check it after the flight (after letting it settle), it'll be around 5.25 to 5.5 and I'll fill it back up to 6.  So I'm with you on that one!

[Bob_Belville]

I don't add partial quarts, I add a quart when level drops to 6 so I stay between 6 and 7. Belly does not get much oil.

[Marauder]

I don't add partial quarts, I add a quart when level drops to 6 so I stay between 6 and 7. Belly does not get much oil.

If I'm over 6.5 quarts my belly looks like a greased pig being prepped for a Hawaiian Luau. I often wondered if the breather tube length has anything to do with this. I know I have the drilled hole in the tube, but I wonder if length in the slip stream has anything to do with it.

[Ragsf15e]

Yep, I wonder the same thing.  I'll take a picture and measure it today.  I'll post some pics and you can see if your breather tube is about the same.  Don't think I have the hole drilled, but I'll check.

[Bob_Belville]

Here's a pic of my breather hose. There's a large hole on the back side near that clamp. The end of the tube is quite close to the cowl flap when closed. 

[Marauder]

Yep, I wonder the same thing. I'll take a picture and measure it today. I'll post some pics and you can see if your breather tube is about the same. Don't think I have the hole drilled, but I'll check.

I just looked at Bob's picture. I think my breather hole is down lower on the tube. I will do some measuring too.

[Ragsf15e]

Ok, I did some measurements, looked at the breather tube and now I have even more questions!  I don't think mine has a hole in it at all except where it vents out below the cowl flap.

 

From Bob's picture, it looks like his doesn't even have a metal tube venting it below the bottom of his cowling?

 

I did a picture with the cowl flap open and closed (doesn't close all the way which could be a different problem - thoughts?) and measured it.

 

Drew

 

[Guest]

Drew,

From all of the Mooneys ive seen your aluminum vent line is installed too low and Bob's is missing.

Clarence

[Bob_Belville]

Clarence, mine is missing on purpose. But there is a large hole in the side of the hose, probably 1/2 or 5/8" D. The hole is maybe 6" up from the end. 

 

When I was researching whether I needed the metal tip I learned there were two reasons to have a hole in the hose: either/both or neither might be true.

 

One reason was that the end of the hose might get plugged with ice cutting off the vent and pressurizing the crank case.

 

Second, the hole might prevent a Bernoulli(?) effect pressure drop creating suction in the tube due to air movement around the end of the tube.

 

But I'd be happy to be corrected, I'm telling you more than I know. 

[Ragsf15e]

Should I cut off an inch or so of the flexible tube and pull the metal tube up higher?  How much should stick out the bottom of the cowl?

 

Should there be a hole in the back like Bob mentions to prevent blockage?  I've heard of that icing as well?

[Marauder]

Should I cut off an inch or so of the flexible tube and pull the metal tube up higher? How much should stick out the bottom of the cowl?

Should there be a hole in the back like Bob mentions to prevent blockage? I've heard of that icing as well?

Mine sits about a inch below the closed cowl flap. There should be a hole in it. Let me get a few pictures of mine and send them along.

[Marauder]

Clarence, mine is missing on purpose. But there is a large hole in the side of the hose, probably 1/2 or 5/8" D. The hole is maybe 6" up from the end.

When I was researching whether I needed the metal tip I learned there were two reasons to have a hole in the hose: either/both or neither might be true.

One reason was that the end of the hose might get plugged with ice cutting off the vent and pressurizing the crank case.

Second, the hole might prevent a Bernoulli(?) effect pressure drop creating suction in the tube due to air movement around the end of the tube.

But I'd be happy to be corrected, I'm telling you more than I know.

Bob I heard both reasons as well. I tend to believe the venturi effect theory.