CO Intrusion in Cabin

Issues pertaining to the TGB/C30X series engine and driveline issues
Post Reply
AppleTech
United States of America
Posts: 43
Joined: Sat Dec 19, 2020 10:11 pm

CO Intrusion in Cabin

Post by AppleTech »

Since I take my kids with me on rides and to shows, I put an aviation CO monitor in the back of the truck where the kids sit. If I let the truck warm up with the doors open it 100% will go off after a few minutes. Normally stops when I'm driving around town. I noticed recently on the highway (between 50 and 60MPH) that it has started going off until I re-open the front windows. I re-sealed the rear window which was loose - that is now watertight. The door seals all SEEM good (and door closure is tight) but I am going to replace anyways just in case fumes are being sucked in through a gap. I know for sure there are various exhaust leaks so next month I'm going to be taking it to a muffler shop to have a new system built out from the mainfold on - flex pipe is super leaky as is the muffler to tailpipe connection. I have replaced the manifold to engine gasket already, which was also leaky.

Any other thoughts on steps I should take to mitigate? The seals around the engine cover seem OK especially since the truck isn't alerting when idling with doors closed - it really seems to be at higher speeds or idling with the doors open that I run into issues. Any thoughts on mitigating? Does anyone recommend a different routing of the exhaust while I have it at a shop? I was thinking of maybe having it run up and over the rear axle and out behind the PS tire instead of crossing under the truck where it might get pinched - I'm presuming that routing is to create a long enough run to massage backpressure?
Jim Molloy
United States of America
Posts: 364
Joined: Sun May 30, 2004 2:16 pm
Location: Sheridan, Oregon
Contact:

Re: CO Intrusion in Cabin

Post by Jim Molloy »

Our AluZn TGB11 has floor drains behind the rear doors of the passenger area. That could be one source of entry from below. You are going to solve the issue of the exhaust leaks. Our latest addition to the TGB family required new mufflers and tail pipe. I chose to order parts from Tatanka Parts and could not be happier with the quality and the fit. LONG before there was the Tatanka option, I needed to replace the exhaust on my first TGB11. The muffler shop I chose gave me a functional exhaust that dumped out just behind the passenger rear door. We will soon be replacing the original exhaust on our AluZn TGB11 and I will be ordering from Tatanka once again.

Best wishing on tracking down the CO gremlins.
Jim Molloy
Waldersee Farm
http://www.northwestmogfest.com
User avatar
VinceAtReal4x4s
Admin
United States of America
Posts: 2035
Joined: Mon Apr 12, 2004 10:36 pm
Location: Ca. or lost in South West USA
Contact:

Re: CO Intrusion in Cabin

Post by VinceAtReal4x4s »

The stock routing works fine. There's little option for other routes anyway. Flexing your axle will likely hit it, there are heat concerns, etc.

I had a far superior exhaust than stock built by a small custom shop. They used a Flowmaster muffler. I actually gained ground clearance and it looked nicer. The modern, plated pipes are much more resistant to rust too.

Sounds like you are saying you have a bunch of leaks so that's where your problem likely lay! Get those fixed and look out for any small openings/seals ripped, etc and it''ll be solved. You are driving a box so the air flow around the cab will be strange and confusing. At certain times you will suck fumes into places even when it seems impossible but overall shouldn't be too bad. I've lived with this forward-cab stuff for many years but found that a sealed system with stock exhaust routing always works well, except for soft top models! The roof hatch can also change the dynamic.

The best solution I found overall to fumes and dust is to have some kind of air vent at the front that you can regulate. The little flip-out vents you used to find on 4x4's work great, like the old FJ40's had near the floorboard for example. The older Gwagens have a direct flow vent option on the dash and I found that very effective at keeping dust from being sucked into the back door area because it positively pressurizes the cabin. The old triangle front-door window fold-out option worked for many cars for a long time. Too bad they went way.

Don't forget that high CO levels can also mean poor carb or timing tuning as well.
"For those who risk, life has a flavor the protected shall never enjoy"

Your donation makes this site possible!

Image
AppleTech
United States of America
Posts: 43
Joined: Sat Dec 19, 2020 10:11 pm

Re: CO Intrusion in Cabin

Post by AppleTech »

Thanks all - I appreciate your input. One thing I noticed is my existing exhaust system has a flex pipe behind the manifold outlet - the pipes look all stock but when I look at the Tatanka replacements they don't have flex pipes. Should I have a flex pipe in there or no? I know the manifolds can be a bit brittle on these trucks.

RE: carb tuning - I think its OK. The truck starts up and idles great. Confirmed timing is 10º dead on. No smoke when warmed up. Whatever I decide to do with the exhaust (stock kit from Tatanka or going to a local shop) I am planning to weld a bung on each downpipe so I can get me a air/fuel meter to make sure each carb is tuned well.
dokatd
United States of America
Posts: 301
Joined: Sun Nov 30, 2008 8:13 pm

Re: CO Intrusion in Cabin

Post by dokatd »

Be careful trusting the CO meter. I have one in my plane and if I put it in certain spots in the cabin it goes off all the time. In fact it was reporting “deadly” amounts, not just sleepy amounts but deadly amounts near my windshield pillar. But 10” back on the window it was in the green all the time. It now sits behind my B pillar on the back door and works as expected. So what I’m saying is you may be getting some eddies of air that are giving you bad readings.

And yes, some tape over the drain holes makes a massive difference.
Post Reply