Episode 27: Exploding Port-a-Potty, Car Pole-Vault

Air Date: March 2, 2005

Lighting a cigarette in a port-a-potty filled with methane gas will cause an explosion.


Not enough gas is produced by the decomposing waste in the port-a-potty for it to possibly be flammable. A person would need to be in a tightly sealed port-a-potty filled with thick methane gas in order for it to be flammable. By the time the gas was thick enough in the air to become flammable the person would have long-since passed out from asphyxiation. Larger amounts of decomposing waste can produce more gas, and sewer gas explosions are a known safety hazard.

A broken driveshaft dragging on the ground can cause a car to pole vault end-over-end if it strikes a pothole.

partly busted

A car cannot be made to go end-over-end by striking a pothole with the driveshaft. The back end of the car can be lifted, but the likelihood of an event like this happening is extremely improbable. More likely is that the driveshaft would be forced into the trunk.


  1. P Skalla says:

    I actually know somebody the “pole vault” myth happened to. The back of the car bucked up in the air about 3-4 feet, and then then drive line buckled and the car dropped (it is just pipe folks)

  2. Yoweigh says:

    I witnessed something similar as well, but the culprit was the exhaust pipe.

  3. Diggity says:

    This is where people get stupid about claiming MB is wrong. Those do not qualify as the myth. The car did not flip end over end in either of those scenarios.

  4. kev dipple says:

    going back about 4 years ago i was driving a bus and the prop shaft uj joint gave up and it dug in and lifted the bus up upto about a foot off the ground but on the type of vehicle i was driving the prop was only 2 feet long needless to say i needed new under crackers afterwards luckily i had nobody on board.

  5. bruce cullenward says:

    thirty years ago I witnessed a panel van drop its driveshaft from behind the engine, it lifted about 4 feet in the air and pivoted sideways and slammed into a tree.

  6. Mack Tosh says:

    I was hoping to at least have a “plausible” for the car pole-vault segment, provided the exact myth could be reproduced under perfect conditions. It certainly would have been entertaining to see…
    BTW, the failed bunny-hop over the radio-flyer was hilarious!

  7. gasttiece says:

    Interestingly as the followers intention take to be this…

  8. DG says:

    I had a 1983 Chevy Chevette and my tail pipe broke in the middle causing the who rear of the car to raise about 3′ or more. The Pipe didn’t break through, but bent and broke off. I had only been driving a short time so it was a bit scary at the time.

  9. Matt London says:

    I was driving on the highway today in my lifted silverado. My driveshaft slammed on the ground and my truck popped up about 4 feet into the air. I was going 70 miles an hour. I am lucky to be alive. I don’t think you can go end over end, but i think sideways is definitely possible. I’d say going 70 sideways in any car, lifted or not could definitely do the job. Drive safely and choose your Mechanic wisely.

  10. Supermonkey says:

    I saw this happen to a 4×4 at a street race.The front shaft broke and dug into the asphalt,flipping the truck and fatally ejecting the passenger.I think the fury didnt flip because ot was low to the ground and extremely heavy,so the shaft broke off the axle end.The driveshaft jamie rigged to separate on command was a stroke of genius!!

  11. Lisa Diggle says:

    Hi Guys, when I red this news report it immediately brought to mind the expolding port-a-potty experiment. This one may need more follow up. Lisa


  12. Leo says:

    in 1980 i was driving my dad’s 1961 Ford F-100 pickup truck when the front yoke of the drive shaft slipped off the spline of the transmission tail shaft. the yoke dug into the street and catapulted the rear of the truck about 4 feet and it caused the rear of the truck to slide sideways. the truck almost tipped over onto it’s right side! i was only going about 15 miles per hour when it happened and there was no pot hole in the road, not even a speed bump. the drive shaft wasn’t damaged at all but i had to walk home to get some tools so i could get the drive shaft back into the tail shaft of the transmission. i found out later that there are two types of yokes that will fit that same transmission. one is called a ‘short yoke’ and the other is called a ‘long yoke’. having the wrong yoke was probably the cause of the problem.

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