How to lose 4 quarts of oil in 3 hours

[floridaflyer]

My Rocket lost 4 quarts of oil during a 3 hour flight. I found out when it took 4 quarts to get it back to 8. Until then I was using about 1 quart every 4 hours and I didn't think much of it. During the flight manifold pressure starting to fluctuate about 4 inches, with oil pressure close to yellow range. I since figured out the MP fluctuation was due to insufficient oil pressure actuating the turbo waste gate. Landed at nearest field and local maintenance facility did leak down, one of the cylinders was around 40 lbs. No oil in exhaust or any other visible leak but lots of oil under belly. The oil was coming out of the crankcase breather tube due to blow by. They pulled the cylinder and put in new ring set and that fixed it. I also noticed the oil was still clear after a 4 hour return flight. So if you're losing an excessive amount of oil this could be due to blow by like it was for me. 

[211º]

Hmmm. Going to keep an eye on this as I too am currently calculating about 0.25 qt of oil used per hour. Thanks for writing this up.

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[bonal]

Did you notice an increase in oil temp

[bonal]

Oh, and welcome to Mooney Space

[kris_adams]

Welcome.  Glad everything worked out for you!

[floridaflyer]

13 minutes ago, bonal said:

Did you notice an increase in oil temp

That's the crazy part, the oil temp went down to 160F. 

[FloridaMan]

Nice, so there's a rocket owner in Florida. Where are you? 

[floridaflyer]

54 minutes ago, Antares said:

Nice, so there's a rocket owner in Florida. Where are you? 

Clearwater.

[FloridaMan]

I had a chrome lined cylinder installed last annual and noticed higher temps and increased oil blown out for the first 50-100 hours after the install. I'm guessing there was increased blowby during break-in. 

[floridaflyer]

UPDATE - IT AIN'T GOOD

So... a year after my initial post and following a top end, zero oil loss in the first 5 hours, then the issue returned with a vengeance: 3 qts oil lost out of the coming out of the crankcase breather in 1 hour...

• New Millenium cylinder assemblies with all compressions in the mid to high 70's. 5 STOH. 1,400 SMOH. Rules out blowby.
• New prop seal. Rules out ram air leaking into the crankcase at speed.
• New oil filler cap seal. Ditto.
• New Airwolf air/oil separator.

The two IA's who worked on the plane are stumped so I'm running out of options. Any suggestions on whom to talk to or take the plane to are appreciated. At this point, selling as-is is the only option I can think of.

[RobertGary1]

Do you have an engine monitor? Are the EGTs mostly in line?

 

-Robert

[floridaflyer]

RobertGary1:

Yes, all EGT's are within 30F of each other. So are CHTs. 

[N201MKTurbo]

You could have blockage in the turbo return oil line. It will blow all the oil out the turbo bearings.

or something else....

[KSMooniac]

You could have blockage in the turbo return oil line. It will blow all the oil out the turbo bearings.
or something else....

Definitely start here, and make sure check valves are installed in the correct orientation and functional.

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[Andy95W]

Yeah, it sure sounds a lot like this other thread yesterday 

 

[floridaflyer]

N201MKTurb and KSMooniac:

Turbo was overhauled 1 year ago. There is no soot on exhaust pipe so I'm not burning any oil, the oil is lost out of the breather. I will ask IA to double check the turbo to make sure there is no air leaking from the turbo compressor side back into the engine through the turbo oil return line.

 

Edited September 29, 2017 by floridaflyer

[floridaflyer]

Andy95W the post you referred to is different, he said:  "Flew from Holland to Vienna a few weeks back and during cruise it hardly uses any oil." I lose 3 qts an hour in flight.

[carusoam]

Oil being pushed out the breather often comes with a signature of high pressure in the engine block.

Mechanics measure that pressure using an ASI.

Does your oil smell like it has adsorbed exhaust odors or turn dark?

Can your mechanic measure the pressure inside the engine block?

Definitely read @MooneyMark MooneyMark's thread for the questions that come up regarding turbo check valves, scavenger pump and start-up issues... 

There is a lot of techno detail outlining all the possibilities of a turbo causing oil loss.

It seems to be a two step process.  

1) the oil drains someplace...

2) then the oil gets pushed overboard in a second step...

The check valves seem to be be able to get installed backwards... setting up this possibility...

PP thoughts only, not a mechanic...

Best regards,

-a-

[floridaflyer]

Carusoam:

All good points. Oil is clear with no smell as it should be given brand new cylinder assemblies and no blowby. I had the ASI hooked up before the top end and it was reading 120 mph instead of the 90 mph max specified in the TCM SB. We'll hook it up again and see what pressure we're getting. 

[drapo]

I don't know about the Rocket, but if I put 8 qts of oil in my IO360 A1A, it will go down to 6 in a matter of an hour or two via the breather tube!

[floridaflyer]

Drapo:

This is a TSIO 520 with 12 qts capacity the oil loss last brought level down to 5 qts which is below minimum of 1/2 capacity per FAA. If it stopped at above 6 qts I would be fine with it although wouldn't have much margin. 

[drapo]

7 hours ago, floridaflyer said:

Drapo:

This is a TSIO 520 with 12 qts capacity the oil loss last brought level down to 5 qts which is below minimum of 1/2 capacity per FAA. If it stopped at above 6 qts I would be fine with it although wouldn't have much margin. 

That is what I meant when I said that I did not know about a Rocket... 

[floridaflyer]

So for what is --hopefully-- the final update on my original post, problem fixed. After top end, new prop seal, new oil filler seals and the turbo O/H just 1 year ago, the culprit was the Airwolf air/oil separator. After I removed it (see the lonely bracket left behind), zero oil loss after 4+ hrs flying at various altitudes. To be fair to Airwolf, the AOS probably didn't have enough downward slope for oil to return to the case via the modified pushrod. It's moot because no oil loss without it. Anybody looking for a lightly used AOS please PM me.

[kris_adams]

So glad you found the culprit.  Thanks for updating us as well.  So few people tend to do that.  As far as the AOS goes, my mechanic took mine off as he said he's seen them cause as many issues as they fix.  If I have to wipe a little oil off the belly that's OK with me!

[floridaflyer]

20 minutes ago, Kris_Adams said:

So glad you found the culprit.  Thanks for updating us as well.  So few people tend to do that.  As far as the AOS goes, my mechanic took mine off as he said he's seen them cause as many issues as they fix.  If I have to wipe a little oil off the belly that's OK with me!

I hear you, I put the AOS in thinking it would be the solution but post-top end, it became the problem!