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High TIT, CHT, and rough running engine (and changing the magneto type)

Yesterday I had to perform a precautionary landing due to some engine trouble. I’m posting here to speculate a bit about the possible reason. The aircraft is now parked at a maintenance shop but due to the upcoming holidays I doubt that I will have fixed whatever broke before January. So there is time to entertain everybody a bit :-)

After taking off I did a long climb to FL190 in one go. That meant about 30 minutes at full power. During the climb temperatures were high but normal. I did feel a bit of vibration but not unusually strong. The OAT on the ground was 0C. The engine was warm before takeoff.

After leveling off the TIT was way too hot at 1750F and after a minute cylinder #5 showed 412F while the others were within the normal range.

I pulled the power back and the CHT on #5 got down below the warning threshold. However, the TIT did not decrease significantly.

Any ideas?

Frequent travels around Europe

Were you able to do a mag test ?

I’m betting on a mag failure.

Since this is a Turbo, do you have pressurized mags? Bendix or Slick ?

Double down if you have pressurized Slick mags !

Last Edited by Michael at 14 Dec 08:39
FAA A&P/IA
LFPN

High CHT normally means a too lean mixture, or ignition too advanced relative to MAP, as you are in a turbo and the other cylinders were ok – I would think too lean would be the primary culprit, either too much air or too little fuel

cylinder 5 injector with a small piece of dirt into would be my first place to go, run the engine with the cowls off and check all exhaust temp with a laser thermometer , even at moderate RPM for a short time this will confirm the engine monitor data.

Ultrasonic cleaning of the injector is likely to be the cure if this is the problem.

Last Edited by A_and_C at 14 Dec 09:50

Blocked injector on #5 ?

As for TIT, are you running LOP ? If so, did you try leaning futher to reduce TIT ?

NeilC
EGPT, LMML

I fly a 22T LOP and know that MAG timing is crucial. If you were able to test fly now, I would suggest a LOP MAG check. However, with just one Cylinder playing up and a high TIT at your usual mixture setting I would get the shop to check for an induction leak on the RH side (1,3,5). An induction leak on that side would give you a higher fuel ratio on either 1,3 or 5 cylinders taking it closer to peak which would give you all the symptoms that you describe.

EGBE (COVENTRY, UK)

I know that one can not compare Cirrus and Cessna, but climbing all the way up to FL 190 at full power that may not be healthy for the engine.
I use full power only a few minutes for take off. Then I reduce to best climb power as recommended in the POH. I don`t know the Cirrus POH.

Berlin, Germany

Last time I climbed with a Cirrus 22TN to FL250 south of Chicago enroute to Florida going back from Oshkosh, we lost the turbo at FL230 and had to make emergency descent and land at the nearest airport. I will think twice before trying such an exercise again :-). Going up high in unpressurised single piston always presents significant risk of something going wrong.
BTW, your Cirrus is equipped with engine monitoring together with other data (airspeed, GPS position, Manifold pressure, OAT etc.). Can you download the file from the flight we are talking about and possibly few flights before that, upload them to Savvy Analysis and publish the graphs, which you get, here on EuroGA? I would like to see the graphs as it might show something you might have missed during the climb.

LKHK, Czech Republic

@highflyer there is no “climb power setting” in the POH. This is a turbo-normalized SR22. The engine also operates near sea-level.

I’m far away from the aircraft now and thus cannot download engine data. I needed to continue my travel.

Having the TAT system means I simply use a certain fuel-flow (16 GAL/hr) and RPM value (2500) and that’s it.

When it happened I was overhead Frankfurt and so a landing at EDFE was convinient. The aircraft is now with the Roeder shop there.

Frequent travels around Europe

I just learned that my right-hand magneto had died. That caused insufficient fuel burn and thus high temperatures

Good to have two mags

Frequent travels around Europe
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