Yes, onions can expire. You can tell if an onion has gone bad by checking for signs of mold, soft spots, or a foul smell. If the onion looks discolored, feels mushy, or has a strong odor, it is likely spoiled and should be discarded.
when it does not work
you know when you are not cotrolling the car.
check it
If you eat it and then throw up. ;)
If it is stale and a very light brown and nothing grows on top of it, then you know you have bad soil.
It as a dark color and it emits a bad order that is easily recognizable
It will probably smell bad or have a noticeably weird flavour to it.
technically, yes. But im not sure if its safe to eat a bad fried onion
Swap it with one you know is good.
Well it all depends if the sound of the engine is abnormal or muffled then it prolly gone bad and if it dont start then well you know its bad
Try smelling it if you still dont know, pour some into a glass and see if it looks clumpy or thick. Dont drink after its gone bad!