Oil Leak

[gevertex]

I went to fly today and noticed that the oil was about 3/4qt lower than last flight. Measured 5.5/8 qts cold on Jan 21 and 6.25/8 qts cold on Jan 15th. Only 1.5 hours of flight time between measurements. So I started looking for oil and found a decent amount of oil. Pictures attached. Also found a screw driver hiding out... Now I know why the engine smelled a little like rubber after a long flight on a hot day.

Opened a ticket with Savvy, but wanting to see if anyone here had any thoughts.

Edited January 22, 2024 by gevertex

[A64Pilot]

I think you need to de-cowl it, degrease it and run it up for 5 min or so and shut down and start looking. Some swear by adding UV dye in the oil but I’ve never had to go that route. There are advanced techniques like spraying dye penetrant developer onto suspected case cracks, but I don’t think you need to go that far, case cracks do occur but are relatively uncommon. I would not worry about them at this point.

I don’t see a smoking gun in the pics. It’s sort of normal depending on how long it’s been since overhaul or manufacture to have seeps.

I use Gunk engine bright, mineral spirits is good too and often is what engine manufacturers recommend as it avoids water, be careful with it though as it’s charcoal lighter fluid. I’m not saying don’t use it just take precaution as you’re spraying a flammable liquid on the entire engine, at least have a fire extinguisher available. I’ve never heard of a single fire from engine cleaning though.

I’m hopefully fixing a leak on my C-85 as we speak, it lost 1 qt of oil in a 30 min flight.

That qt of oil covered the entire belly and when I got back after lunch there were puddles of oil going all the way back to the tailwheel, probably four puddles in all.

If you lost 3/4 quart of oil in a leak, it makes an epic mess, the entire belly would literally be dripping oil.

[Shadrach]

A slight accumulation around cylinder bases is not uncommon. However, the river running down the exhaust pipe is concerning. I would start with a check of the area around the base of the oil filler neck and prop governor. 

[gevertex]

I had the top half of the cowl off yesterday. Need to figure out how to get the bottom half off, looks like detaching the cowl flaps actuator arm is required.

It’s only been ~70 hours tach since overhaul. 

[RoundTwo]

None of the stains you show around the cylinder bases look to be bad enough to result in the quantity you lost in that amount of time. Either you didn’t lose as much as you thought, or you haven’t found the real culprit. I agree with removing the cowl and do a thorough degrease and then run it  for 10 minutes or so at idle, or a bit above. Any leak of the size required to lose that quantity will be noticeable. 

What work was done recently? Since you found a screwdriver, I’m guessing someone was doing something on the engine and they left something loose.

[Shadrach]

Just now, gevertex said:

I had the top half of the cowl off yesterday. Need to figure out how to get the bottom half off, looks like detaching the cowl flaps actuator arm is required.

It’s only been ~70 hours tach since overhaul. 

Yes, any assembly issues typically show up in the first 100hrs, which could include case fretting. Inspect the parting flange (where the case halves meet) on the underside of the engine.

[RoundTwo]

11 minutes ago, gevertex said:

I had the top half of the cowl off yesterday. Need to figure out how to get the bottom half off, looks like detaching the cowl flaps actuator arm is required.

It’s only been ~70 hours tach since overhaul. 

Did they just change the oil?

[dzeleski]

Oil leaks that I have had to track down on my J:

• Cylinder head drain tube clamps, and the tubes themselves
• Oil filter adapter gasket
• Oil sump bolts/nuts loose
• Slightly stuck open oil quick drain
• Oil/Air separator mounting issues, causes tank to not drain correctly and make a mess

 

Other places to check:

• Prop Governor
• Loose Mag
• Crank seal
• Push rod tubes

Edited January 22, 2024 by dzeleski

[gevertex]

1 hour ago, RoundTwo said:

None of the stains you show around the cylinder bases look to be bad enough to result in the quantity you lost in that amount of time. Either you didn’t lose as much as you thought, or you haven’t found the real culprit. I agree with removing the cowl and do a thorough degrease and then run it  for 10 minutes or so at idle, or a bit above. Any leak of the size required to lose that quantity will be noticeable. 

What work was done recently? Since you found a screwdriver, I’m guessing someone was doing something on the engine and they left something loose.

Engine was overhauled ~70 hours ago along with all accessories. So really a significant amount of work. I had noticed some of this oil prior, and loose header tubes were found / corrected and cited as the cause. That fix it didn't seem to correct the amount of oil I was seeing in the cowl + this seems to be worse than prior given the oil quantity measured. I suppose I could be mistaken at the amount of oil lost (factors like temperature, slope of the ground, what else?) could impact measurements. Even so it's rather a lot of oil IMO. What do you think?

Edited January 22, 2024 by gevertex

[gevertex]

1 hour ago, RoundTwo said:

Did they just change the oil?

No. It's due for another oil change basically now. I am at 29 hours on this oil change.

[gevertex]

44 minutes ago, dzeleski said:

Oil leaks that I have had to track down on my J:

• Cylinder head drain tube clamps, and the tubes themselves
• Oil filter adapter gasket
• Oil sump bolts/nuts loose
• Slightly stuck open oil quick drain
• Oil/Air separator mounting issues, causes tank to not drain correctly and make a mess

 

Other places to check:

• Prop Governor
• Loose Mag
• Crank seal
• Push rod tubes

Mag seems to be clean

 

2 hours ago, A64Pilot said:

I think you need to de-cowl it, degrease it and run it up for 5 min or so and shut down and start looking. Some swear by adding UV dye in the oil but I’ve never had to go that route. There are advanced techniques like spraying dye penetrant developer onto suspected case cracks, but I don’t think you need to go that far, case cracks do occur but are relatively uncommon. I would not worry about them at this point.

I don’t see a smoking gun in the pics. It’s sort of normal depending on how long it’s been since overhaul or manufacture to have seeps.

I use Gunk engine bright, mineral spirits is good too and often is what engine manufacturers recommend as it avoids water, be careful with it though as it’s charcoal lighter fluid. I’m not saying don’t use it just take precaution as you’re spraying a flammable liquid on the entire engine, at least have a fire extinguisher available. I’ve never heard of a single fire from engine cleaning though.

I’m hopefully fixing a leak on my C-85 as we speak, it lost 1 qt of oil in a 30 min flight.

That qt of oil covered the entire belly and when I got back after lunch there were puddles of oil going all the way back to the tailwheel, probably four puddles in all.

If you lost 3/4 quart of oil in a leak, it makes an epic mess, the entire belly would literally be dripping oil.

Definitely didn't notice that level of leakage on the belly, etc. What got me looking more was the oil on the nose wheel door and the lower level of oil I noticed during pre-flight.

[Shadrach]

I would check the mag and hold down nuts as well.

[gevertex]

1 hour ago, Shadrach said:

Yes, any assembly issues typically show up in the first 100hrs, which could include case fretting. Inspect the parting flange (where the case halves meet) on the underside of the engine.

Will check that.

[dzeleski]

One thing to add is that where the oil sits does not really determine where its leaking from. So dont think because its in X location it must be directly above said location. The air flow in the cowl moves oil ALL over the place. A tiny amount of oil makes a HUGE mess.

The fastest way to find the leak is as said above, clean the engine, taxi around using higher then normal taxi RPM (raises oil pressure), come back and remove the cowl. It should be pretty obvious. Personally I would not be flying that airplane with an oil leak that was touching the exhaust, thats a great way to have an engine fire.

[EricJ]

2 hours ago, gevertex said:

I had the top half of the cowl off yesterday. Need to figure out how to get the bottom half off, looks like detaching the cowl flaps actuator arm is required.

Those are easy to disconnect.  Grab the actuator where it connects to the cowl flap and lift up, it'll then disconnect from the ball on the flap.

The only other complication with the lower cowl is to disconnect the landing light.    There are two fasteners on the lowest part of the cowl between the cowl flaps, too.

[redbaron1982]

44 minutes ago, EricJ said:

The only other complication with the lower cowl is to disconnect the landing light.

Don't forget this one! Or you will have your lower cowl hanging from two wires! Ask me how I know... I did a checklist for myself so I don't forget now. In my case I have also the TKS light that illuminates the leading edge of the left wing.

[RoundTwo]

2 hours ago, gevertex said:

Engine was overhauled ~70 hours ago along with all accessories. So really a significant amount of work. I had noticed some of this oil prior, and loose header tubes were found / corrected and cited as the cause. That fix it didn't seem to correct the amount of oil I was seeing in the cowl + this seems to be worse than prior given the oil quantity measured. I suppose I could be mistaken at the amount of oil lost (factors like temperature, slope of the ground, what else?) could impact measurements. Even so it's rather a lot of oil IMO. What do you think?

It could be several things, so best bet is to clean it and taxi it around, no need to cowl it up for a taxi, and look for evidence. If it’s bad, it will be very obvious. The problem finding a leak after flying is that the oil is blown everywhere, and the source is hard to detect unless it’s a gusher. 

[McMooney]

check your oil cooler,  sneaky leak that is, esp if the oil is clean

[gevertex]

8 hours ago, EricJ said:

Those are easy to disconnect.  Grab the actuator where it connects to the cowl flap and lift up, it'll then disconnect from the ball on the flap.

The only other complication with the lower cowl is to disconnect the landing light.    There are two fasteners on the lowest part of the cowl between the cowl flaps, too.

This was super helpful. I got the lower cowl off tonight!  Luckily landing lights are in the wings. I’ll post an update shortly. 

[gevertex]

3 hours ago, McMooney said:

check your oil cooler,  sneaky leak that is, esp if the oil is clean

Checked. It looked clean to me. Oil cooler is basically new too. 

[gevertex]

I went ahead and took off the bottom cowl and found a few interesting things. First, found what appears to be an oil line (is that an oil return line?) on cylinder #3 that had it's fastener backed off a few turns. It wasn't even hand tight. Most things under and around that were pretty much soaked with oil. Thinking that could be the primary culprit.

I was able to confirm with a few other pictures two push rod tube seals that had some leakage. This is concerning as this is a recently overhauled engine. There may be good news there, it's possible this is old. I do remember after the avionics install seeing and asking about the clips that hold the push rod tubes in place. The A&P that I asked immediately indicated it was wrong and fixed it. So I am hoping the seepage is from before he fixed those.

Also found some leakage from one of the intake header tubes. Looks pretty minor, but you can see where oil has leaked down the side of the tube all the way to the bottom.

Also found a leaking oil pressure transducer.

Also found a loose screw that appeared to be holding a fuel line.

I did also find some brown oil looking substance between the crank case halves, but it's dry and appears to be some kind of sealant. Took a picture of the only part of the bottom of the crankcase half seam I could see and it looked clean also.

Took a picture of the belly. It does look sooty, but I can't tell if this is too much or not. I have never cleaned down there.

Most of the lower part of the engine was soaked in oil including wires leading to the alternator. This appears to be connected to the oil return line leak as those wires run up below that line.

There was also oil on the bottom of cylinder #4.

Most of the cylinders had seepage I could see. Also disappointing as this is a new engine. I definitely wouldn't expect any leaks from any of the seals attaching primary engine components this early.

[201Steve]

The engine only has 70 hours on it, may I inquire, who did the overhaul?

[gevertex]

20 minutes ago, 201Steve said:

The engine only has 70 hours on it, may I inquire, who did the overhaul?

Jewell Aviation out of Kennet, MO did the engine.

AGL Aviation did the engine reinstall.

Carolina Avionics did the avionics install including the engine sensors.

Edited January 23, 2024 by gevertex

[201Steve]

30 minutes ago, gevertex said:

Jewell Aviation out of Kennet, MO did the engine.

This is precisely the reason I asked the question. It was sounding far too familiar reading through your growing list of discoveries. 
 

 

it’s a long read but some of it may sound familiar. I don’t mean to startle you and as a fellow aircraft owner I sincerely hope your engine is fine, but David Jewell is the most inept mechanic I have ever had the displeasure of knowing. They cut corners, do cheap work, and as you’ll read, I have made an effort to let it be known. 
 

Don’t expect him to do anything about it, but from a safety perspective, I would have another mechanic go through the engine as best you can. Boroscope, filter analysis, oil samples, visual checks, and torques. If you have a J with a dual magneto, Make certain that he used the correct clamps and used the correct torque. Mine was dangerously loose and he said he didn’t agree with the torque value called out in Lycoming SB. 
 

since you are a savvy client, be sure to let them know who built the engine. 

[PT20J]

If it were mine, I would tighten everything up, solvent wash the engine and ground run it up to operating temperature and then inspect to see if it's still leaking. I would carefully inspect EVERYTHING firewall forward and fix anything questionable before replacing the cowling. Fortunately the case parting line does not appear to be leaking -- somebody just applied a bit too much sealant. And, I'd keep their screwdriver.