Briefly running engine in garage

[OutbackL130]

I was adjusting throttle linkage on a small 9hp engine while briefly running it inside my shop with the garage door down, but had my 10,000 CFM exhaust fans going. When I first started the engine there was a significant amount of smoke that filled the shop from burning oil in the cylinder, but the air cleared out within 20 seconds. The complete air exchange rate of my shop with the fans going is less than 30 seconds and the breeze generated is like being at a windy beach. Is it safe to operate an engine inside if exhaust fans are on?

I don't work on engines often but it got me wondering what are some ways mechanics stay safe from carbon monoxide when running an engine indoors while doing engine repairs? I know some mechanics clamp a hose to the exhaust to bring it outside. I read that having the garage door open is not enough as the carbon monoxide levels can still become dangerous in just a few minutes.

 

[Tollster]

I believe brief use is acceptable but not over a repetitive short course of time, but none the less should be prevented is you have alternatives. CO2 is an odorless gas that will build up over time in the body, so chronic intake can be just as deadly as an acute intake as your body cannot release the gas as fast as it builds up.
Same with exhaust leaks, long term expose can creep up on you and you may never know it, at least that what I was taught when I raced two stroke dirt bikes.

 

[OutbackL130]

I want to mention the engine was not idling, I just started it up and shut it off several times to check throttle adjustment.

It probably would be a good idea to buy a co meter just to be safe for next time I work on an engine or even for checking co levels inside vehicles due to possible exhaust leaks.

 

[Coyote machine]

I want to mention the engine was not idling, I just started it up and shut it off several times to check throttle adjustment.

It probably would be a good idea to buy a co meter just to be safe for next time I work on an engine or even for checking co levels inside vehicles due to possible exhaust leaks.

Odorless, tasteless, colorless DEADLY gas. There is NO acceptable level over repeated or single episodic exposure. I ran a foreign auto repair service for over ten years and had to get out of the business due to health issues, one of which was exposure to co and other chemicals. I still get severe headaches if exposed to any co fumes, even if outdoors in otherwise fresh air environment.
Forget the co meter of interior levels, just don't allow yourself to be exposed. It will kill you and you won't 'see' it coming.

 

[Coyote machine]

I believe brief use is acceptable but not over a repetitive short course of time, but none the less should be prevented is you have alternatives. CO2 is an odorless gas that will build up over time in the body, so chronic intake can be just as deadly as an acute intake as your body cannot release the gas as fast as it builds up.
Same with exhaust leaks, long term expose can creep up on you and you may never know it, at least that what I was taught when I raced two stroke dirt bikes.

BTW, it's NOT CO2, which is carbon dioxide, but CO which is the deadly gas, carbon monoxide, to which you refer.

 

[OutbackL130]

I'm surprised more people aren't hurt by co after looking at a chart on the cdc website of how quickly co builds up in a room even with ventilation such as open doors and blowers. There was one test result they did that showed co rises to harmful levels within 10 seconds of the engine being turned on. **** it takes me longer than that to back my riding mower out of the garage while maneuvering around everything in there.

Is it a bad idea to park the car or lawn mower in the garage unless they are pushed in and out without starting the engine?

 

[ericher69]

Odorless, tasteless, colorless DEADLY gas. There is NO acceptable level .Forget the co meter of interior levels, just don't allow yourself to be exposed. It will kill you and you won't 'see' it coming.

Gotta say this is Terrible advice.

It is law just recently in Ontario to have a CO monitor in the home if you have ANY fuel burning device.

I have one in my shop. Cheap insurance for $20

 

[Coyote machine]

I want to mention the engine was not idling, I just started it up and shut it off several times to check throttle adjustment.

It probably would be a good idea to buy a co meter just to be safe for next time I work on an engine or even for checking co levels inside vehicles due to possible exhaust leaks.

I'm NOT saying don't have a co detector. I am saying that knowing you're working around/in a co polluted environment is CRAZY AND relying on a meter to tell you it's at a harmful level is also nuts. Interior of the car monitored with a co meter is also a problem. Presence of co is DEADLY period. Drive the mower in, immediately shut off engine, push or roll it to where it needs to go.

Gotta say this is Terrible advice.

It is law just recently in Ontario to have a CO monitor in the home if you have ANY fuel burning device.

I have one in my shop. Cheap insurance for $20

Read above in red. This is what I'm saying, not what I didn't make clear enough earlier. Household co detectors register high levels of co. Exposure to lower levels or known to be emitting levels from an engine are way to risky to rely solely on a detector. I'm saying just don't expose oneself for any reason to however 'controlled' an amount one thinks one can 'tolerate.' It will kill you sooner than later. Don't risk exposure, fans or blowers or whatever aside; NOT worth the risk! Hope that's more clear.

 

[sixdogs]

Odorless, tasteless, colorless DEADLY gas. There is NO acceptable level over repeated or single episodic exposure.
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...

It will kill you and you won't 'see' it coming.

Agreed. This will kill you while you think you are still safe.

 

[Coyote machine]

Agreed. This will kill you while you think you are still safe.

To further press the point about co detectors being largely ineffective, EXCEPT when high levels of co are present, my tenant next door is an assistant fire chief and recently went to a fire call where everyone inside was dead. There were co detectors, but the couple didn't have enough time to get out. And even if they could have escaped the co by very short overall time/exposure many die from smoke inhalation while trying to escape in residential episodes.
Co will render one unconscious, then dead. I had a co detector that was considered real sensitive mounted at the top of my cellar stairwell to alert to low levels of co from the oil fired boiler. I added hard wired co and smoke detectors and attic/garage/ boiler room heat detectors, that alarm on rate of rise in heat. They're all backed up by batteries and redundancy via my security system. co kills, period. Don't temp fate by exposure that can be avoided.