Oil leak- what is this on 0290d2?

[Cardiff Kook]

What is this covering on my 0-290d2? I think I have an oil leak coming from there. Wherever the leak is coming from it appears to intensify when the plane is on.

[RaisedByWolves]

On the 320's if i remember right should be the prop governor, there should be a gasket under there. Probably old and brittle

[TurboBeaver]

Vacuum pump pad ???........ As Tom suggested, likely just a bad gasket?
E

[DENNY]

What they said. Easy job to replace the gasket. I would do it sooner than latter, mine went and pumped out 6 quarts in about 3 min. DENNY

[BC12D-4-85]

Nuts tight?

Gary

[stewartb]

When you take that cover off check it for flatness. If the previous owner over-torqued the bolts the flange corners will be bent and a new gasket won’t solve anything. You’ll need to flatten it and then add a new gasket.

A sheet of sandpaper applied to a piece of glass with aerosol adhesive will allow you to lap it flat. Maybe other guys have other techniques.

[skywagon8a]

Vacuum pump pad ........ As Tom says likely just a bad gasket?
E

That's where the two position control valve for the Sensenich C-2FM two position prop goes. The oil to the prop is connected where that allen plug is located. The vacuum pump drive is on the upper left of the case.

That was a nice prop which was AD noted out of existence.

[Cardiff Kook]

Where can i find the part number and order?

Im new to all this but i my mechanic is super backed up so if i want this done i probably need to start being more proactive.

[stewartb]

Ask around. Lots of guys will have one or two on a shelf after getting a new engine and bolting on alternators and prop governors. I gave one away not long ago. I may have another. I’ll look.

[stid2677]

Ask around. Lots of guys will have one or two on a shelf after getting a new engine and bolting on alternators and prop governors. I gave one away not long ago. I may have another. I’ll look.

Thank you for it too,, it is on my Cub.

[Cardiff Kook]

Ask around. Lots of guys will have one or two on a shelf after getting a new engine and bolting on alternators and prop governors. I gave one away not long ago. I may have another. I’ll look.

Im not sure what i would even ask for?? Whats it called? Ha.

Would they need to have an 0290D2? Or is rhe sam on an 0320? I am full newb on this stuff.

[BC12D-4-85]

Engine parts for O-290's> https://www.lycoming.com/sites/defau...PC-102-1_0.pdf
Engine parts for O-320's> https://www.lycoming.com/sites/defau...g%20PC-103.pdf

Gary

[frequent_flyer]

Where can i find the part number and order?

It's often a lot easier to make a replacement gasket out of suitable gasket stock. Simply lay the gasket paper on the part and tap round the edges and holes with a light ball peen hammer. I have made quite a few that way including quite intricate carb gaskets. You do what you have to if the part is not available.

You may also find that good quality sealants do better than the paper gaskets originally fitted. If you do that make sure the gasket thickness is not critical to the assembly. It's not likely to be for this simple cover application.

[BC12D-4-85]

Works to help seal things> https://www.aircraftspruce.com/catal...ezturnlube.php

Gary

[stewartb]

Seals fuel fittings, not accessory cover plates!

Kardiff, go to O’Reillys or your local equal and buy some gasket material. Use your old gasket to trace the shape and cut it with an Xacto or utility knife. Don’t worry about perfect, just seal the flange. Easy peasy. If it leaks again? I’ll send you a new cover plate, but odds are you don’t need it. Don’t be afraid of being a newbie. You’ve got this.

[BC12D-4-85]

Stewart it's also a gasket paste. Read the ad. I've used it for years.

Gary

[stewartb]

I do what Lycoming recommends. When I deviate for gaskets? I use Hylomar. EZ Turn is for fuel fittings.

[BC12D-4-85]

More on preferred gasket sealants> https://www.shortwingpipers.org/foru...agneto-gaskets

Gary

[frequent_flyer]

If the joint needs to be moved after assembly it seems obvious that one would not use a hardening sealant on both sides of the gasket. Magnetos need to move for timing. Cover plates don't need to be rotated. If you want to be able to remove something, like a rocker cover, without changing the gasket every time then bond one side and grease the other.

[DENNY]

I would definitely use a gasket and not just some type of sealant!! Take the time to get the right part!!!! DENNY

[wireweinie]

That's where the two position control valve for the Sensenich C-2FM two position prop goes. The oil to the prop is connected where that allen plug is located. The vacuum pump drive is on the upper left of the case.

That was a nice prop which was AD noted out of existence.

As usual, Pete is right. I did not find it in the O-290 book but look in the O-320 book (PC-103). Figure 2-7, items 9 and 10.

Web

[BC12D-4-85]

Gaskets get compressed and stressed by heat cycles especially with petroleum present. New and proper is best. But, after 57 yrs of dealing with that vs available parts in Alaska some of us learned to fix things when new simply wasn't available. It's hard to loose old habits and become a parts changer.

Gary

[Steve Pierce]

I have made plenty of gaskets in my lifetime but for an airplane engine I would buy the gasket from Aircraft Spruce or the like. A thin coat of EZ Turn works very well on gaskets to help seal and make them easier to get off when the time comes. I use it on mag and oil screen gaskets all the time.

[Cardiff Kook]

Cool. P/N 69551 GASKET, Accessory pad cover. I'm learning! Thanks.

When this gets replaced is the oil going to have to be dropped?

Should I use this opportunity to replace other gaskets that may or may not be leaking?

If I'm placing an aircraft spruce order for a $1.95/part- anything else I should order to just have on hand as well?

Thanks all!

[skywagon8a]

When this gets replaced is the oil going to have to be dropped?

No. All the oil is contained in the sump which is that large casting below the crankcase. The one the carburetor is bolted to and the intake tubes come out of the side of.

[Cardiff Kook]

No. All the oil is contained in the sump which is that large casting below the crankcase. The one the carburetor is bolted to and the intake tubes come out of the side of.

Makes sense. I guess that is true of any piston engine. The sump always holds 99% of the oil when off/sitting. Embarrassingly, I Never really thought about it.

[cubdrvr]

I have made plenty of gaskets in my lifetime but for an airplane engine I would buy the gasket from Aircraft Spruce or the like. A thin coat of EZ Turn works very well on gaskets to help seal and make them easier to get off when the time comes. I use it on mag and oil screen gaskets all the time.

What he said............

[frequent_flyer]

The sump always holds 99% of the oil when off/sitting.

Quite a lot less than 99% in the sump if the engine has a filter. On my O-360 and IO-360 I add 7 qt at oil change and maintain the dipstick at about 5 qt for local flying. Lycomings piss oil out the breather if run with high oil levels.

[BC12D-4-85]

One way to learn about fits is to remove all gasket and foreign material from the mating surfaces, then apply a very thin coating of commercial Prussian Blue to one. Refasten then separate to look for any lack of transfer of that dye's color. That can indicate part warpage that makes a gasket's job tougher. Lap the surfaces as suggested above to reflatten if a problem.

Gary

[DENNY]

Cool. P/N 69551 GASKET, Accessory pad cover. I'm learning! Thanks.

When this gets replaced is the oil going to have to be dropped?

Should I use this opportunity to replace other gaskets that may or may not be leaking?

If I'm placing an aircraft spruce order for a $1.95/part- anything else I should order to just have on hand as well?

Thanks all!

You should also replace the star washers. Get some EZ turn if you do not have a tube.
DENNY

[Cardiff Kook]

This ended up not being that gasket.

It looks like it is the gasket area under the spin on oil filter, which is new. Not the gasket between filter and screw- but gasket between that and engine. You can see a little drip here:





Spent a few hours tracking it down.

Then i did a run and my left mag is having an issue. Plane ownership is fun!

[skywagon8a]

Spent a few hours tracking it down.

Then i did a run and my left mag is having an issue. Plane ownership is fun!

Wipe off that drop of oil and monitor the issue. If you chased every drop, you'd never go flying.

The mag issue could just be as simple as a dirty spark plug. Don't just assume the worst.

[BC12D-4-85]

What is the issue with the left mag? Just running rough or larger rpm drop than right? Is it a recent event?

Gary

[Cardiff Kook]

What is the issue with the left mag? Just running rough or larger rpm drop than right? Is it a recent event?

Gary

Let mag always has been kind of an issue for 175 drop. Right always about 100z. Left 175+ most days

Today after messing around i did a mag test and it dropped 250 and plane was shuddering a bit. Right mag was fine- maybe 100. Tried it 3 or four times.


Maybe i fouled the plugs trying to fix that leak.

In any case needs addressed.

[BC12D-4-85]

I'm not an A&P but know several over the years that have offered their advice. If it were my issue out of town I'd tighten the mag harness to plug connection then run the engine on both just rich of lean cutoff for a few minutes to maybe clean it some of carbon and built cup oil, then run on the bad mag for a few more. Stop and see if one cylinder or exhaust pipe is noticeably cooler than the rest due to bad firing - touch exhaust briefly with candle for example - colder cylinder = slower melt. Note what plugs that mag fires and check them first as well as their plug wire connections. If they look ok, swap them with similar plugs from the other mag and run to see if the issue moves with the plugs to the other mag or still remains with the first bad mag. If that's unproductive, get an A&P to look over both mags, wiring, and plugs. Or just do that now and save yourself some grief.

Gary

[skywagon8a]

Let mag always has been kind of an issue for 175 drop. Right always about 100z. Left 175+ most days

Today after messing around i did a mag test and it dropped 250 and plane was shuddering a bit. Right mag was fine- maybe 100. Tried it 3 or four times.


Maybe i fouled the plugs trying to fix that leak.

In any case needs addressed.

Start by pulling and cleaning all the plugs. One inoperative plug can cause a 250 drop. With one inoperative plug it is only running on three cylinders.

[frequent_flyer]

Rough run-up with excessive mag drop is not uncommon if you taxi, or spend a long time, at full rich mixture on the ground. If you don't already, taxi with leaned mixture and keep RPM at or above 1,000. If you experience rough running on one mag during run-up then go to full throttle and lean the mixture just above the point where engine falters. Hold that for 30 seconds then try mag drop check again.

Not an A&P but I do own, maintain, and fly an O-360 with over 3,000 hours since overhaul.

[BC12D-4-85]

Spark plugs have a range of normal internal resistance. Talked about here and there...~5K ohms and depends on manufacturer. Helps reduce radio static and may create a hotter spark if and when it fires. If dropped to the floor the internal resistance can be compromised. Cleaning is fine...bomb or testing in a device under air pressure similar to what the cylinder produces during compression is even better. So, it's possible to have more than one issue with a spark plug, cleaning only addresses one.

Same for mags internally and timing....wires...wire to plug connections...and any P-lead capacitor if installed can fail. Unless notes are kept over time to detect changes, it's hard to just jump in and say something's getting worse that's actually been F* all along.

Gary

[Cardiff Kook]

Rough run-up with excessive mag drop is not uncommon if you taxi, or spend a long time, at full rich mixture on the ground. If you don't already, taxi with leaned mixture and keep RPM at or above 1,000. If you experience rough running on one mag during run-up then go to full throttle and lean the mixture just above the point where engine falters. Hold that for 30 seconds then try mag drop check again.

Not an A&P but I do own, maintain, and fly an O-360 with over 3,000 hours since overhaul.

I thought about this. I may have fouled them when i was trying to find the oil leak.

Full throttle and leaned out is the ticket? Just want to check what rpm i should be at to try to burn it off. Dont want to break anything else.

[skukum12]

If you have a primer, minimize the number of strokes used during cold starts or first start of the day. Experiment with fewer strokes until you find the least number needed to start the motor in varying atmospheric conditions. Even down to half strokes.

If you are fouling plugs during a warm start, don't use the primer at all and keep the throttle closed until the motor starts to fire and catch it with the throttle. Over priming is the quickest route to fouled plugs for me.