Stuck Oil Control Ring

[Lee A.]

TSIO-550 with oil consumption 1 QT every 2-3 flight hours.

Compressions all good.  Borescope seems to indicate oil in cylinder 1, 3, and 5 at times.

Been following this for over a year.  Otherwise engine runs perfect!

Cylinders are otherwise in great shape with 1000 HR STOH.

Engine is 1900 HRS.

Not planning to overhaul.

Things I have tried to fix what I think may be a stuck oil control ring:

Solvent wash in the cylinders.

Frequent oil changes (oil gets dirty in 10-20 hrs due to blow by).

Changed the intake valve guide seals (in case they were leaking.)

Nothing has fixed it.  I suspect a stuck oil control ring on cylinders 1,3, and/or 5.

My mechanic has offered to pull cylinders 1,3,5 (the suspected cylinders) and replace piston and rings.

Options:

Complete top overhaul - not sure why I would do this...cylinders look ok on borescope.

Replace piston/rings on cylinders 1,3, and/or 5....not sure how to narrow down if it is just 1 or all 3 cylinders.

Overhaul cylinders 1,3,5.

Replace cylinders 1,3,5......with maybe Millennium cylinders.

Labor to take half the engine apart to do any work on cylinders 1,3, or 5 is about $4k

 

Thoughts?  Comments?

 

Thanks,

Lee

 

[Guest]

It seems to be a common theme with 550’s sticking rings.  Be sure you have a plan before pulling cylinders, they seem to be rare at the moment.  We have some on order now and don’t expect them till late March.  Even gasket sets seem to be rare.

Clarence 

[tmo]

I believe I've read about people putting 1/2 of a quart of car Mobil1 0W20 for a couple hours before an oil change to clean stuck rings, as a measure of last resort.

[jetdriven]

You can Hydro lock a can of Berrymans B12 chemtool in the cylinder and let it sit for a couple days, this tends to soften up the carbon, it may free up your oil control ring stuck issue

[EricJ]

6 hours ago, tmo said:

I believe I've read about people putting 1/2 of a quart of car Mobil1 0W20 for a couple hours before an oil change to clean stuck rings, as a measure of last resort.

MMO (Marvel Mystery Oil), is also a common thing to use for aircraft engines.    In a car engine when you really want to un-fubar things, SeaFoam or Automatic Transmission Fluid works well.    We've rehabbed car engines that had been sitting in the desert for years this way.

 

[PT20J]

1 hour ago, EricJ said:

MMO (Marvel Mystery Oil), is also a common thing to use for aircraft engines.    In a car engine when you really want to un-fubar things, SeaFoam or Automatic Transmission Fluid works well.    We've rehabbed car engines that had been sitting in the desert for years this way.

 

Mechanic friend's favorite penetrating oil is 50/50 mix of Dexron III and Stoddard solvent.