CO infiltration**update

[NewMoon]

So we have ~40 hrs on an Acclaim we just bought a month ago.  Just flew 3 legs with our new CO digital monitor. 

Getting 35-55ppm readings on the climb. Consistent 9ppm in cruise.

In speaking with Dan Bass (shared his contamination story at Mooney Summit) he is getting 0ppm in climb and cruise. He suggested we look for exhaust leak(s). Headed to Cole Aviation on Monday.

What levels are other pilots seeing? Any Acclaim owners have experience in chasing exhaust leaks?

thx for any input.

 

[Oscar Avalle]

On my M20C I get around 9ppm on the ground, 4 on climb and 0 in flight.

 

Oscar 

[802flyer]

I see 5-10 taxiing around on the ground, zero while flying. Point of clarification: it’s carbon monoxide (CO) not carbon dioxide (CO2).


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[NewMoon]

Just now, 802flyer said:

I see 5-10 taxiing around on the ground, zero while flying. Point of clarification: it’s carbon monoxide (CO) not carbon dioxide (CO2).


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thx

[larryb]

I had an '84J and now have a '97 Encore. In both I often see 10 to 20ppm in the climb and 0 to 5 in cruise. Sometimes the numbers vary.   I've had a couple scenarios with much higher readings:

1. Runup or startup with significant tailwind. This caused > 50 ppm and the alarm to sound.
2. Landing with cowl flaps fully open.  This can also cause the alarm to sound. 

 

 

[LANCECASPER]

It's most likely your door seal. On an Acclaim pay close attention to your turbo transition.

 

[NewMoon]

Just now, LANCECASPER said:

I wouldn't worry about CO2 (carbon dioxide)- you expel it every time you breathe.

CO (carbon monoxide) is what you need to worry about.

It's most likely your door seal. On an Acclaim pay close attention to your turbo transition.

 

Great, when you say door seal, the black one around the door edge or the interior trim seal?

[LANCECASPER]

Just now, NewMoon said:

Great, when you say door seal, the black one around the door edge or the interior trim seal?

the black one around the door edge. In a dark hangar have someone move a flashlight all around the perimeter of the door. If it lets light in, it's letting air and CO in. The Acclaim has an exhaust pipe on each side. But pull the cowl off and really look closely at the turbo transition.

 

 

[NewMoon]

1 minute ago, LANCECASPER said:

the black one around the door edge. In a dark hangar have someone move a flashlight all around the perimeter of the door. If it lets light in, it's letting air and CO in. The Acclaim has an exhaust pipe on each side. But pull the cowl off and really look closely at the turbo transition.

 

 

excellent,  Joe Cole is going to pressure up the exhaust and spray on the soap to find leaks.

I know for sure the seal is split all along the edge so I expect it's not sealing well at all. Appreciate your insight. 

[LANCECASPER]

Just now, NewMoon said:

excellent,  Joe Cole is going to pressure up the exhaust and spray on the soap to find leaks.

I know for sure the seal is split all along the edge so I expect it's not sealing well at all. Appreciate your insight. 

If you get a good seal on there, installed properly, you will be surprised at how much quieter the cabin is.

[NewMoon]

1 minute ago, LANCECASPER said:

If you get a good seal on there, installed properly, you will be surprised at how much quieter the cabin is.

yeh I was wondering about that, it does seems quite loud but I had no point of reference. 

[Justin Schmidt]

I only see 15ppm on the ground after 10 min and depends on winds. Otherwise it is 0ppm. All the seems in the cabin floor are sealed with tape.

[GeeBee]

Ovation. On the ground with storm vent open maybe 10. In flight in any regime, heat on or off 0.

[N201MKTurbo]

I see zero all the time, except when I shut down and open the door, then I see 10-15.

The other day I was taxiing in. the wind was a little gusty. My CO monitor started beeping and flashing red lights (I didn't know it did that) it read 85. I couldn't find anything wrong. The next flight it was zero again. It must have just been a strang gust of wind.

[Pinecone]

On my 252/Encore I get 0 at all times with the door closed.

If I open the door on the ground for ventilation, I will see 4 PPM.

[Flash]

9 hours ago, NewMoon said:

excellent,  Joe Cole is going to pressure up the exhaust and spray on the soap to find leaks.

Could you please tell Joey that Mike Knobler said hello. He's a great guy and an excellent mechanic.

Also, I generally see 0 on my CO monitor in flight but sometimes see 4 or so when on the ground.

Edited October 21, 2023 by Flash

[carusoam]

Great report NewMoon!

1) You are definitely seeing higher than usual CO readings…

2) It is time to find the trouble spot.

3) Joey Cole is the right resource to visit.

4) Things to look for… turbo engines have V-clamps holding exhaust tubes together… small leaks often show a gray dusty pattern where the exhaust is escaping…

5) V-clamps come with rigid procedures for tightening and re-use….  Improper re-use can lead to disastrous outcomes… (torque, and number of times it gets torqued)

6) If the leak occurs before the turbo… this is a very high pressure, high temperature, place to have an exhaust leak…

7) Worst case… the leak gets worse quickly, and has a cutting torch effect under the cowling…

8) Post a follow up when you find the source…

It will probably be another good saved by @DanM20C story…  

Turbo exhaust leaks can be very serious trouble…

We can always invite @mike_elliott to the conversation…  Mike has some additional insight on this type of challenge…

 

PP thoughts only, not a mechanic…

Best regards,

-a-

 

 

[MikeOH]

Another ZERO all the time for my 70F.  Very occasionally during run up, if the wind is right, I'll see 10-15 ppm.

SOMETHING IS WRONG if you're seeing 35-55 ppm!

[NewMoon]

6 hours ago, Flash said:

Could you please tell Joey that Mike Knobler said hello. He's a great guy and an excellent mechanic.

Also, I generally see 0 on my CO monitor in flight but sometimes see 4 or so when on the ground.

Yes I will, appreciate the positive feed on him. Is it Joe or Joey? 

[NewMoon]

Thx Mike and -a-, yes definitely an issue that needs to find a fix. Glad Joey was able to get us in on Monday. 

Will definitely report back and appreciative Mike E suggested the new digital CO monitor.  

[Flash]

9 hours ago, NewMoon said:

Yes I will, appreciate the positive feed on him. Is it Joe or Joey? 

Thanks. Either is fine, I think. You can ask him which he prefers these days. He was my mechanic from 2002-2009, when he was in Rome, Ga. and I was in Atlanta. We've both moved since.

[NewMoon]

24 minutes ago, Flash said:

Thanks. Either is fine, I think. You can ask him which he prefers these days. He was my mechanic from 2002-2009, when he was in Rome, Ga. and I was in Atlanta. We've both moved since.

great thx, excited to work with him

[mike_elliott]

Scott, you can use your new CO detector to spot where in the cockpit (most likely wheel well or door seal) by seeing where it suddenly goes higher. A second person helps here.

[NewMoon]

So..the CO infiltration was coming from the pilot side turbo. a small leak got much worse over the past 20 hrs.

On start up this morning,  leg mag check generated a very rough running engine. Didn't seem like a MAG. Great shop on the field in NC pulled bottom plugs on #1, 3 and 5. #3 & 5 were virtually dead because of oil fouling. we cleaned them and set out for Cole in GA. 

Arrived at Cole and immediately pulled all plugs, 3 and 5 oiled up again and lots of oil in the bottom.  after scoping them all (just had boroscope done at prebuy 40 hrs ago, sent to Continental) the decision was made to pull them all off and start fresh.

Inactivity has killed this goose, be very careful with engines that have lacked usage. It's never a good thing and I should have known. 

[NewMoon]

On 10/22/2023 at 5:49 AM, mike_elliott said:

Scott, you can use your new CO detector to spot where in the cockpit (most likely wheel well or door seal) by seeing where it suddenly goes higher. A second person helps here.

thx Mike