Turbocharged Manifold Pressure

[mshac]

The plane does have a data-recording engine monitoring system. I may spend the $100 and send the files from the last few flights to Savvy Aviation for their experts to analyze.

Anybody here ever use their service before?

[GAdams]

Your lists looks appropriate. I would use Savvy based upon what I have seen and been told about the companies reputation. I personally have no first hand experience. Best to analyze before "attacking with tools"

The fellow with a 55 PSI cylinder. I wouldn't condemn that cylinder right away without doing a borescope. Followed up by lapping the valves if the borescope inspections leads you to believe a valve problem exists. Burnt valves also can be corrected without removing the cylinder in various cases. Again look at the information from EAA/Savvy on YouTube and go from there.

[patrolpilot]

Originally Posted by mshac

The plane does have a data-recording engine monitoring system. I may spend the $100 and send the files from the last few flights to Savvy Aviation for their experts to analyze.

Anybody here ever use their service before?

I'm a SAAVY Guy; Pro and Breakdown. I haven't had any problems, just receive the interval engine reports. I'm going to turn the maintenance over to them as soon as I get the aftermath of my latest annual over and that portion of the records digitized.

I also use Blackstone for the oil analysis.

[Joes]

Compression in Context | Savvy Aviation Resourceshttps://resources.savvyaviation.com › articles_eaaPDF

TCM issued Service Bulletin M84-15 to provide official guidance to mechanics about performing compression tests on TCM engines.

Very informative way to analyze cylinder health. Eliminates a lot of old wifes tales. Regards, Joe

[Jerry De Santis]

I hope it is not the turbocharger. My planes has been down 10 months waiting for one and I paid dearly for it. Good luck!

[Dan schultz]

I would first look for any intake leaks from the compressor discharge through the whole system including the sonic nozzle and the hose going to the pre cooler.

Compression checks like you have done, 55 should still be ok if there is not significant burning of the exhaust valve or play in the guides.

Check the exhaust by pressurizing from the tailpipe with your shop vac then using soapy water to check for leaks, bubbles are ok, but blowing bubbles away not good. I have a new Acorn rear exhaust and had to eliminate the springs.

Unfortunately if those things are ok, time to dig further, looking at the waste gate and turbo. You can take the tailpipe off and check the play of the turbine shaft. If there is significant play up and down of the shaft that is not good. Cessna does not object to using a front turbo on the rear engine as up to S/N 98 they used the same one. Not approval from them, depends on how your IA looks at that. My opinion is that it is a minor alteration and no other approval needed, however, I am not your IA.

The wastegate when closed may have significant erosion on the butterfly valve causing blow by.

And then of course it could just be the controller, or the waste gate actuator may have picked up some trash from the oil, take the two hose fittings loose and blow it out both ways.

The maintenance manual has good troubleshooting on the system.

Dan
N67S
Finally got mine flying after 2.5 years, flew it about 12 hours the last few days.

[MD83driver]

Congratulations Dan on getting your plane up into the air! Now starts the fine tuning process. About the same time it took me to get mine going.
Your going to love that plane!