Yes. You need to open the plumb, & you have an air vent there.
Clogged drain or toilet. Also check the vent holes under the rim and clean the out.
This could be caused by either a clogged vent line or lack of vent to outside atmosphere. It sounds like your drainage system is starving for air and is trying to pull air from the path of least resistance, the toilet. Also, it may be caused by the drain line itself being partially clogged
Yes if the vent pipe is 4" and vertical by code and there is nothing connected between your toilet tee and where you would connect your new toilet tee. If not worried about codes then yes you can connect to a 3" vent line if no other vent lines are connected down stream. If you have a vent pipe that is less then 3" and or you have other vents connected between your old toilet tee and your new toilet tee then NO you can not connect a new tee for your toilet.
As close as possible is best, but there just has to be a vent so that the air that is in the line has somewhere to go so that the liquid isn't trying to compress it. The closer the vent is to the toilet, the better it will flush.
No, that is why it is called a vent pipe not a soil line
Your drain line is plugged somewhere after your shower and toilet line are connected. The reason for the gurgle in your toilet is because air is trapped in the drain and your toilet is the closest place for air to flow to. If you had a vent on your toilet trap arm then it would gurgle in the vent rather in your toilet but your drain is still plugged and needs to be snaked out and maybe your drain line needs to be examined for right grade or broken.
There is an overflow pipe on every tub. There is no further need to vent.
The very bottom hose is for fuel overflow, it should be vented to atmosphere.
where one toilet is draining to its own unshared line, the line can be 3" but once both toilets are draining to the same line, it needs to be 4". in other words, from the first toilet to the second toilet can be 3" but past the second toilet needs to be 4". there needs to be a vent downstream of the second toilet in the direction of flow if there is another fixture of any kind downstream of the two toilets.
location of overflow vent on 1972 VW Beetle IRS rear suspension
no it has a vent if it is coming out the vent it is over full.
Yes as ALL fixtures need to have the vent placed above the FLOOD LEVEL RIM