High oil consumption on an IO-540

[rotoiti]

My RV-10 has an old engine (about 5,000 hours on it). It was top overhauled before installing in the -10, and it had installed all new, nickel cylinders at that time.

The oil consumption was always high but during 4 years (and 300 hours) I owned the airplane, the consumption increased from 1 quart per 3.5 hours to 2 quarts per 3 hours. Oil analysis shows increased nickel but that is in line with nickel cylinders.

This is still in-spec by Lycoming standards (current consumption 0.66 qt/h vs. 0.87 qt/h maximum) and my mechanic recommends just adding oil. Looking for a second (or third or...) opinion

Thanks!

[William]

That?s a very high oil consumption rate. How many hours are on the cylinders?

[RONSIM]

Our -10, ECI (new) Nickel cylinders had high oil consumption (qt every 4 hrs). We "broke in" with mineral oil and switched to Aeroshell after 50 hrs -- oil consumption remained high ----- THEN, we found out that ECI recommended Phillips XC for break-in and permanent use. We switched to the Phillips, and, over time, the oil consumption stabilized at quart every 10-12 hrs. Just a data point, but worked for us.

I use the Phillips on my new (at the time) ECIs on the -6A and certainly have no complaints.

Ron

[rotoiti]

385 hours on the cylinders, since 2012 I believe.

[grubbat]

If the cylinders weren’t broken in properly, they may never break in no matter how much time they have on them. Assuming valves are good, pull them, crosshatch the cyl, install new rings, then break in properly.
Good luck !!

[William]

Originally Posted by rotoiti

385 hours on the cylinders, since 2012 I believe.

With that high of a oil burn with such low hours on your cylinders I would definitely be pulling the cylinders for inspection. What do your spark plugs look like? How about the inside of your exhaust pipes?

Bill

[rotoiti]

Yes, I have no idea if the cylinders were broken in properly. I bought this airplane when it had 106 hours on it.

Spark plugs look fine, no fouling. I have dual LSE Plasma 3. My mechanic insists on aviation plugs, so that's what is installed there now. Not sure if that could be the reason.

Compression is fine, two cylinders are in 69-70 range, rest is 75-77.

[RV8iator]

Originally Posted by rotoiti

Yes, I have no idea if the cylinders were broken in properly. I bought this airplane when it had 106 hours on it.

Spark plugs look fine, no fouling. I have dual LSE Plasma 3. My mechanic insists on aviation plugs, so that's what is installed there now. Not sure if that could be the reason.

Compression is fine, two cylinders are in 69-70 range, rest is 75-77.

I’d get a second opinion on mechanics.

[Carl Froehlich]

Originally Posted by RV8iator

I’d get a second opinion on mechanics.

+1 on Jerry’s comment. While I agree this has nothing to do with your excessive oil burn, use the recommended plug. If your mechanic does not understand electronic ignitions, don’t let him work them.

Just to make sure - I assume you are not filling up the sump to 12 qts. Most people run around 8 or 9 qts. Anymore will just blow out the crankcase vent.

Carl

[edsong]

Carl is right. Us guys that have 4 cyl engines run 6 quarts max.

Eddy