Why we cut filters

[flyeyes]

Thought I'd post this for those of us who do our own oil changes, but haven't seen a problem yet.

This filter was off of our IO-550 after a mag failure which resulted in advanced timing and detonation in a cylinder.

The engine came off and went back to TCM.

You can see the small chunks of metal everywhere, mostly non-magnetic
http://img87.imageshack.us/img87/490...nfilteral2.jpg

[flyeyes]

Here is the plug from the bad cylinder:

[ao.frog]

Hi.

Thanks for the pics and story. Glad everything went well with the people onboard!

What kind of mags where on the plane? (just courious)

[Geico266]

Originally Posted by ao.frog

What kind of mags where on the plane? (just courious)

Yes, inquiring minds want to know.

[Bill Wightman]

So, do you think the mag failure and resulting detonation lead to what we see in the filter? Or is all the filter contamination simply coincidental with the mag problem?

[flyeyes]

Originally Posted by ao.frog

Hi.

(snip)

What kind of mags where on the plane? (just courious)

They were stock "Continental" mags, which are really just relabeled Bendix mags. They came new on the certified IO-550.

The problem occurred at about 600 total time in service. about 100 hours earlier, both mags were inspected in accordance withe the SB recommending 500 hour inspections.

Fortunately, all of our paperwork was squeaky clean, we had carefully documented every bit of required and recommended maintenance, and we had two weeks of TCM "Platinum" warranty left.

TCM has an analytical lab which went through the engine and especially the mag. They sort of implied that it we had used aftermarket parts for the SB we'd be on out own, but fortunately we had used OEM parts and had all the paperwork.

[flyeyes]

Originally Posted by Bill Wightman

So, do you think the mag failure and resulting detonation lead to what we see in the filter? Or is all the filter contamination simply coincidental with the mag problem?

No question at all.

This was the sixth leg the airplane had flown that week, everything including oil levels and mag checks had been normal.

First indication was a sudden CHT redline on one cylinder which didn't respond to a power reduction and mixture going full rich. Less than a minute later the same CHT went offscale low.

This happened in cruise at a relatively low power setting, and the two (very experienced) pilots on board both thought that it was the CHT probe. They discussed whether the six-cylinder continental was running rough but decided it was probably not. As they reduced power for descent they changed their minds, and the FBO called them to tell them the airplane was smoking badly in the pattern. After shutdown, the oil level was at 3 quarts.

We pulled the plugs and borescoped the #3 cylinder--it looked like someone had been beating on it with a ball-peen hammer and half of the exhaust valve was missing.

We didn't go any further since TCM threatened us with loss of warranty coverage if we did any more disassembly or troubleshooting. We just pulled the motor and trucked it to Mobile.

[grantcarruthers]

What aircraft?? Sorry if it's above but I didn't see it?

[flyeyes]

Originally Posted by grantcarruthers

What aircraft?? Sorry if it's above but I didn't see it?

Cirrus SR22

[DanH]

Could you describe the mechanics of the mag failure?

Boy, I hope I never see an oil filter like that one!