High Oil consumption on a Low time Engine

[FlyboyKC]

Looking for thoughts on what could be causing some higher oil consumption.
Oil consumption:  on a fresh oil change with 6.5qts and a new filter, I used 4 Quarts in 20 hours or just shy of 6 quarts in 26 hours  (this was over a period of a month, I did a lot of summer travels, )

- Time on the Engine Since Major: 543 hrs (and has been regularly ran, meaning no long periods of inactivity)
- Engine:  0360 180hp
- Compression's cold, 77,70,79,77/80  (as of today)
- Oil Temp (normal range 190 - 205)
- CHTs 279/313/331/313  ETGs 1350/1300/1268/1300
- Usually run 2400 - 2500 RPM with MP ~22 at 7000 - 9000
- Spark Plugs look good, no excessive amounts of oil on them. (at least of the top plugs, didn't pull the bottoms based on compression)
- Exhaust pipe looks normal (inside)
- No oil leaks found (engine is pretty dry), no oily mess on the belly. (Only oil leak found was slight drip from the oil drain, after a week there was just a small spot on the floor of the hanger)
- Engine has Superior Millennium Steal cylinders (no chrome).
- Oil Brand Phillips XC 20X50 and using CamGuard as an oil additive. Oil changes at 25 -50 hours intervals.

Since I have owned the plane from back in 2015 @253 hours SMOH, my oil samples have come back with elevated levels of Iron, and Chromium. Nickel and Copper were also elevated on the previous samples but not on the latest. (so some improvement). While the Iron and Copper readings have been improving, its only been minimally. (We have been monitoring at the last couple of annuals). Now that I have some trend data, my oil consumption has been increasing between sample readings. My biggest red flag was my most recent summer trip were I have spent flying from Kansas City to Syracuse NY (~7 flight hours) and was down ~2 quarts when I went to preflight for the return trip.  On the return trip it was about 8 hours back, and it used 2 quarts as well.

The engine seems to run fine, no plug fowling, strong. No indication there is a problem other than its using oil faster than I would like. Without pulling all the cylinders and re-ringing my A&P them my A&P is not sure how to troubleshoot any further? 

While I don't mind carrying extra oil around, I think my engine is trying to tell me something. The "what" I am not sure... Anyone got any ideas or suggestions?

Thanks

Neal

 

[skydvrboy]

My plane uses one quart every 4-5 hours and I've talked to both the A&P and the IA about it.  Both say it's a little on the high side, but still within normal limits.

[INA201]

1 hour ago, bluehighwayflyer said:

I bought my J with 1400 hours on a factory reman 12 years ago. I quickly discovered that it burned a quart every 5-6 hours when the oil was fresh and that the burn rate increased to a quart every 4-5 hours as my regular 30 hour oil change intervals drew near. Everything else was nominal.  The oil consumption concerned me initially as every Lycoming I had previously owned burned a quart every 8-10 hours.  Like @skydvrboy‘s, my IA told me not to worry about it. 

12 years later I’m at TBO and nothing has changed. I don’t worry about it any more. I’m assuming it was a poor break-in but who knows. 

Jim

Same here!

I also have a normal exhaust pipe and a little blow by but very minimal.  

The fact that you have a change in consumption  is where you need to look into why it is changing.  I was concerned as well but haven’t noticed a change in consumption on my end.  You might could switch to 100w plus for a while and that may do the trick. Please let us know what you find out. 

[Mooneymite]

What's your oil pressure at cruise RPM?

What is the oil pressure at idle RPM?

[Don Heene]

I have a 68 M20C and if I fill it over 6 Qts. There's blow by.  Most of this ends up on the belly of the aircraft.   If 6 Qts and under it uses about a quart every 10 hours.  

Try with just 5 Qts in it to see how it burns.  I wouldn't go below 5 Qts because you need it for cooling the engine.  

[Bartman]

Mine has 1900 hours and has some known leaks. After an oil change with Aeroshell 100W I add a he first quart after about 6 hrs, but after that it’s every 4 hrs. At about 30 hrs on the oil I change and back to 6 hrs. It leaks but the exhaust is clean plugs are clean and we will hopefully keep going and watch for a change.  

[carusoam]

Figure out where the oil is going...

1) lots goes out the engine vent hose....

• more goes out when the oil is at its highest level...
• more goes out during climb using High attitudes...
• Lots of T/Os leads to higher oil missing...
• Pattern work can be a combination of high power, high rpm, and sending oil towards the vent...
• oil splashing, case pressurization, and High levels of oil, conspire to cover the belly...

2) some goes out in other places...

• old valve cover seals,
• old oil return lines,
• cracked cases near a cylinder stud
• a few other seals have left their marks too...

3) Check the case vent tube to see how much is coming out there

 

4) when looking for oil on spark plugs... the bottom plugs are usually the ones to check... excess oil is a drip here and there... gravity has a way of pulling the drips down toward the lower plugs while the engine isn’t working...

5) Any oil inside the cowl?

6) Any oil escaping out the front of the cowl?

My M20C liked to vent oil overboard... and leak out several old cork seals... and oil return lines from the valve covers...

PP thoughts only, not a mechanic...

Best regards,

-a-