Turbo overhaul

[Kim Geyer]

We use Main Turbo. Not sure how their prices are compared to others, but have not had any problems. Also check the scavange line on the turbo (the bottom line) and see if it's loose where it connects to the starter drive. If it's loose it could cause your oil consumption problem.

[rmorris]

Originally Posted by Kim Geyer

We use Main Turbo. Not sure how their prices are compared to others, but have not had any problems. Also check the scavange line on the turbo (the bottom line) and see if it's loose where it connects to the starter drive. If it's loose it could cause your oil consumption problem.

I'll have them check that connection, thanks.
The airspeed indicator to oil filler tube showed high case pressure during run up on ground. I've akready committed to turbo overhaul and 3 cyl replacement, so will be frustrated if it was a hose connection...esoecially after 4 diff mechanics looked at issue. But I guess you live and learn

[JAG]

I hate to see 3 cylinders being pulled...
If I read correctly, 4 out of 5 mechanics said to monitor - what was the result? How many hours did you monitor? What were the compression's? If you lowered your oil level a little, did this change your oil consumption?

A friend of mine who used to have his own engine overhaul shop (and whom I respect his knowledge) told me on the IO 360 not to get my underwear in a bunch if I have a low compression on a single cylinder. He said the engines were known to have the rings turn and line up, causing compression loss. He indicated that if it was blow-by into the crank, just keep running it and check again in 20 hours (if all other indications were good of course). He said he would often see the compression go back up as the rings turn a little. Not saying this is what happened to you, but if you do have blow-by past the rings, it pressurizes the case and can push oil out the breather. Did you have more than usual oil on the belly? Did you have the turbo boroscoped to look for any evidence of oil leakage?

It just seems weird that this all of sudden happened after the annual as you indicated.
Food for thought for the future. I don't mind changing cylinders...I just don't like paying for them.

Jeff

[AV8ing]

+1 for Main Turbo in CA !

(and -1,000 for ATC in FL: NEVER AGAIN - CRIMINALS ! )

[rmorris]

Originally Posted by JAG

I hate to see 3 cylinders being pulled...
If I read correctly, 4 out of 5 mechanics said to monitor - what was the result? How many hours did you monitor? What were the compression's? If you lowered your oil level a little, did this change your oil consumption?

A friend of mine who used to have his own engine overhaul shop (and whom I respect his knowledge) told me on the IO 360 not to get my underwear in a bunch if I have a low compression on a single cylinder. He said the engines were known to have the rings turn and line up, causing compression loss. He indicated that if it was blow-by into the crank, just keep running it and check again in 20 hours (if all other indications were good of course). He said he would often see the compression go back up as the rings turn a little. Not saying this is what happened to you, but if you do have blow-by past the rings, it pressurizes the case and can push oil out the breather. Did you have more than usual oil on the belly? Did you have the turbo boroscoped to look for any evidence of oil leakage?

It just seems weird that this all of sudden happened after the annual as you indicated.
Food for thought for the future. I don't mind changing cylinders...I just don't like paying for them.

Jeff

Yep, more than usual oil on belly, had all cylinders borescoped.
I was told same thing about the rings might have turned...but it had been going on for months. Despite that, they asked me to fly it another 10 hours, record oil, and return...I said enough is enough, after the 4th mechanic failed to find anything conclusive.
but my wife did ask a couple of hours ago if all this work wil solve the problem....I sure hope so
in the end I had the mags pulled as well for 500hr inspection, and they both failed resistance check, so overhauling them. Replacing 3 cylinders on one side, and new push rode tubes as well to make it all fancy new. all new hardware on anything that was taken off, especially turbo system. Overhauling both turbo controller, wastegate, and turbo itself.
so almost half a top overhaul anyway, ATC in CA has the system and is doing thr overhaul now. I will let you all know with an update post how it goes.
Main responded with aggressive pricing, and good pitch, but they were literally an hour after I had already shipped to Mary at ATC.
So far, having good vibes from Mary....stay tuned.

[AV8ing]

"ATC in CA has the system and is doing thr overhaul now"

'Shoulda gone to Main ...