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IO-390 Oil Consumption

Jetmart

Well Known Member
Looking for some current experience on oil consumption during break in and what it ultimately stabilizes at on the IO-390.
I have done a forum search but did not come across much recent discussion on the topic although there are a lot more flying.
 
This is just my personal experience: I installed a factory new 390 a couple of years ago (under the then Lycoming experimental program). After the prescribed break in flights, my initial oil consumption was relatively high. Prior experience with breaking in 360s was that after around an hour of full power flight the CHTs would drop noticeably, and oil consumption after break in would drop to decent low levels quickly. With a little bit of alarm, I discussed this with Lycoming and was informed that with the 390 series a new type of substantially harder oil rings were being used, and they break in much slower. I was advised to keep running break in oil until the consumption dropped and stabilized and expect that to take up to 50 hours. In my case it was 75! And even after that, the oil consumption kept dropping a bit more over time, and has converged to around a quart in 10 to 12 hours. Aeroshell W100 consumption is noticeably higher than Phillips X/C. I'm not totally happy with this level of consumption, but have been told it is OK for the 390 and at 450 hours now my compressions run 79/80 to 80/80! So, I guess I am happy...
 
Oil Consumption

I also have a 390 on a 14A and around 70 hours the consumption seemed to stabilize around one quart every 7 to 8 hours. It was not that much higher the previous 20 hours. Now it's 8 to 9 hours per quart at 130 hours. Compressions looked good first annual. I known other 390 operators and there consumption not much different if not higher than mine. Using Aeroshell W100. Oil analysis and screen check look ok. Will keep flying and monitoring.
 
I am at 200hrs now and the oil consumption seems to have improved all through the 1st 100hrs. I would note that I never fill above 6 quarts which has helped a lot with elimination of oil going out the vent and mistakenly assuming it was burned. I added 1.5qts between my last oil changes with 50hr interval.
 
I have the same experience as Chris with about 1-2 quarts/50 hours at 205 hours. It definitely likes being less than 7 quarts.
 
I am in phase 1 with about 18 hours total. I regularly top it off to 6 quart mark. I burned about a quart every 2 hours until about 13.5 total hours. At about the 13 hour mark the CHT’s dropped about 30 degrees, the oil temps dropped about 20 degrees, and I topped off the oil with 1/2 a quart today after about 4.5 hours since last fill. I have been running hard most of those hours to break in the motor. Guess maybe most of the break in is done.
Hope that helps.
 
I am at 60 engine hours. I ran Aeroshell 80 for break-in and switched to Phillips XC 20W-50 just recently, with no flights on that oil yet. My first few oil changes were at 10, 35, and 60 hours. My oil consumption seemed to be about 1 quart per 10 hours by the end of the Aeroshell 80 period.
 
Mine is taking a while to break in (I think)

My IO-390 is at about 85 hours and it is still burning 1 quart every 5 hours. I fill to about 6 1/2 quarts and let it drop to 5 1/2. My cylinder head temps make it up to only 300-305 after leaning. So cylinder head temp-wise, mine seems broken in but old consumption-wise, it doesn't seem to be.
 
Expecting a long break in.

I’m at 28 hours and burning 1 qt every 5 hours. Operate from 6 down to 5 on the stick.

I ran the first 20 hours very hard with no slow flight, and only in last few hours did I work through some of the slow flight stalls, stability checks etc.

Based on other’s who have broke in the io-390 I’m expecting a long break in process and even then have read this engine does like oil. I plan to run it hard with mineral oil at least to 75 hours prior to switching, if not more.
 
another data point

When I did my training in the factory -14A they were running it at 5 qt & only adding when it reached 4 qt. I have lowered my fill limit to 5 and have found my "usage" to decrease dramatically.
 
IO-390 T-bolt oil

After straight mineral up to 11 hours break-in, then Aeroshell W100 till 42 hrs, then went from Aeroshell W100 to Phillips 20W-50. Watched it closely from 42 to 53 hours; 7.0 qts down to 6.0 qts in 11 hours. Added 0.5 qt, will watch that to see how many hours to get down to 5.5 qt.
 
At 120 hours I am also around 7-8 hrs per quart. One interesting note…..last week at Oshkosh I was holding at Rush Lake for 50 minutes flying at 90 knots which required only 25% power. I burned 3/4 of a quart during that short flight. I assume the very low power setting did not allow the rings to expand against the cylinder wall and it sucked in oil. I also noticed more oil accumulation on the bottom skin afterwards
 
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