Normal O-360 Oil Consumption?

Hi all - I have a new O-360-A1A with 92 hours on it, and in the last 40 hours oil consumption has been about 2.5 qt of Exxon Elite 20W-50, which averages out to about 1 qt every 16 hours. Lycoming's manual for the engine says oil consumption of between 0.39 and 0.80 qt/hr is acceptable, but those numbers look awfully generous to me; maybe OK for a worn engine approaching TBO, but not a new-ish one.

So, is my engine in the "normal" range, based on real word experience? I should note here that even when keeping it at a max of 6 qt. on the dipstick, I still get oil dripping from the breather tube. From reading previous discussions I presume that even though venting of oil through the breather gets heavier when the engine is filled above 6 qt, there should always be some small amount showing up there, even when the engine is operated with less that 6 qt in the sump.

I get about 22 hrs to the qt. I broke my engine in using Aeroshell Oil 80 for 50 hrs. I changed the oil and filter after 1 hour of ground ops, again at 25 hrs, and again at 50 hrs. I then switched to Aeroshell 15W50. I add 8 qts when I change the oil. After running the stick shows about 7. I add a qt when the level gets to 6 or slightly below (about 22 hrs), then change again at 35 or 30 hours. I have very little residue on the bottom of my plane, even after mild aerobatics.

Mine is a new Van's 0-360 A1A purchased through Van's and picked up at the factory in Williamsport.

Roberta

One note

in an air cooled engine, with tolerances as *big* as they are, oil use is a good thing in an airplane engine.... within reason and that's why Lyc publishes such numbers.

As for engines. They should be broken in with mineral oil until the oil consumptions stabilizes. Then and only then should you switch to an AD oil.

Example. I have a brand new Cessna 182. It ran the phillip "M" 20-50 from the factory and I ran it for 100 hours. I talked to lycoming about STD procedure and it was their recommendation, that when *new*, running mineral for longer is better. Ya see, if you switch before it's broken in, you can actually hurt your engine.

Anyway, I do oil changes at 25 hours, filters at 50 and a sample at each filter change. I usually see 1qt of use between changes. I also fill to 8 (or 9 if new filter), then I don't add until it gets close to 6. I've found that anything more and I just blow it out and all over the belly.... Mind you, this is on a IO-540, but I did the same thing on a new 172 with an IO-360.

YMMV

Break In Oil

Right, I used Phillips M 20W-50 for the first 50 hrs and then switched to the AD oil, so I believe that break in was correct and successful (plus I worked hard at running the engine at 75%, or at least 65%, in the first 10 hours, which was a PITA considering what I really wanted to do was lots of landing practice...). And, there tends to be very minimal oil film on the belly. Sounds as though my current oil consumption is in the ballpark.

Yep. thats about normal. The new big bore Continentals seem to do even better (no loss between oil changes) but unfortunitly, the don't fit on RV's. Our 35+ year oil O-360A1A burns a quart every 3 hours, and has since we started flying it 600+ hours ago. It had 900hrs on it at the time, and had been sitting for 11 years.

Yep about right

Rutus said:

Hi all - I have a new O-360-A1A with 92 hours on it, and in the last 40 hours oil consumption has been about 2.5 qt of Exxon Elite 20W-50, which averages out to about 1 qt every 16 hours. Lycoming's manual for the engine says oil consumption of between 0.39 and 0.80 qt/hr is acceptable, but those numbers look awfully generous to me; maybe OK for a worn engine approaching TBO, but not a new-ish one.

So, is my engine in the "normal" range, based on real word experience? I should note here that even when keeping it at a max of 6 qt. on the dipstick, I still get oil dripping from the breather tube. From reading previous discussions I presume that even though venting of oil through the breather gets heavier when the engine is filled above 6 qt, there should always be some small amount showing up there, even when the engine is operated with less that 6 qt in the sump.

Click to expand...

First I think the oil use you are quoting is for break-in. Too much or too little oil use (1/.39 = 2.6 hr/qt) may indicate a problem with the oil rings for example. It is just a ball park parameter for a break-in engine? If you are using 6-8 hr/qt, I think your engine is OK but getting tired. I never saw a small Lyc use more than that, but sure they can, that is just my experience with some 2000 hr engines (about 8-10 hr/qt).

16 hr/qts sounds good. It will very on how you fly, over time. I usually have seen that to about 18 hr/qts (mid time engine).

Oil dripping from breather? It should not be excessive. Not a fan of, or feel you need an air/oil separator, but you should route the hose up as much as possible before it turn down. Also do you route it over the exhaust pipe to burn the oil off?

As far as dip stick it shows 6 qts easily. I am not sure what you mean. I think it will read down to 3 qts or less, but never checked. 6 qts is plenty high on the dip. G

Lycoming says that an engine can use up to a quart every 2 hours before it is considered "bad." Ours uses a quart every 3-4 hours. I've also seen a 172 recently that was about that bad. Average is probably about 8-12 for a mid time engine.

Where did you see that O

osxuser said:

Lycoming says that an engine can use up to a quart every 2 hours before it is considered "bad." Ours uses a quart every 3-4 hours. I've also seen a 172 recently that was about that bad. Average is probably about 8-12 for a mid time engine.

Click to expand...

Interesting where did you find that 2 qt number. I believe you but that is a lot of oil. I would be less than happy. I guess if it runs right adding oil is cheaper than a top OH. G

gmcjetpilot said:

Interesting where did you find that 2 qt number. I believe you but that is a lot of oil. I would be less than happy. I guess if it runs right adding oil is cheaper than a top OH. G

Click to expand...

Here

.006 X BHP X 4 / 7.4 = Qt/Hr.

On an O-360 A1A HP = 180 so we get .58Qt/Hr or a bit over a quart every two hours. Less than happy is an understatement. We HAVE to run fine wires in the bottom because of of the amount of oil that finds it's way into the cylinders. I've been pushing my pops to overhaul it, but he won't until something major goes wrong with it. Not ideal, but I don't feel it's dangerous by any strech or I wouldn't fly it.