You have good answers in the thread and probably have decided on your solution. Let's talk about the future, too.
I've been using mushroom style plugs for well over a decade and surely have tens of thousands of miles on plugged tires. Maybe some would consider my attitude on the subject ummm, cavalier. Every tire I've "repaired" in this way was a clearly screw/nail/round puncture. Yours looks scary to me. Find the budget and get a new tire.
Also get a plug kit for future just-in-case. They work, even if you don't care to use a holed tire until the end of it's life, a plug can get you back to a place where the tire can be replaced, just treat it like a doughnut spare for a car and go gently.
I can't seem to figure out how to edit my comment on kbin. I thought of one newer than Rush fom a band I've come to enjoy highly and hasn't been posted yet:
There's a beauty and peacefulness to it that's hard to describe. The music will stick with you, too.
Information, not criticism. It's written "en masse"
I'd like to suggest a different reason for the likely judgement: You didn't see the obvious (in his view) sign for the fitting rooms.
Neither of you has to be 100% wrong in the situation. Just because he spends up 40 hours a week seeing that sign and 100% thinks it is GLARINGLY obvious doesn't mean you 100% didn't even try looking for the sign and possibly distracted him from a (perceived) important task to make up for your laziness.
It's a balance. You can both be 50% objectively correct or any variation of levels. The sign could have been higher or lower or a different look than you were used to AND you only glanced around and didn't really stop to look.
I know for a fact that I've been on both sides of this kind of scenario. Would bet most could find one of each in their lives, too. So it's a learning experience, remember that what is obvious/simple for one person (you/someone else) isn't obvious to another person (someone else/you) and try to act accordingly.
But the fart comment is very insightful, you know?
There are two sides that a closer can be mounted on, often called the "pull side" and the "push side". Which side it's on changes how the arm needs to be mounted. There are a few ways for that change to be made and the closer we're looking at is mounted in a way that .... "fell out of favour" I guess.
Instead of changing the way the arm attaches, there is a special mounting plate attached to the jam. When the door is open, the entire closer and mounting plate are out in the open space of the door. My best guess is that this obstruction that could knock a tall person in the head or get damaged by moving large objects through the opening (or just preventing smart people from trying) is why it's almost never done anymore.
HTH!
Plenty of good thoughts in other comments, but absolutely do not "disassemble" that door closer. There is a heavy spring inside which has a slight potential of causing injury. Even without that hazard, you will never get the spring back in place and the oil refilled.
The installation looks weird and the design of the closer itself is different than I am personally used to. I'm guessing you aren't in the U.S.? Even if you aren't all the basic principles remain the same.
It is possible that the hydraulic fluid has leaked out as others have stated. This is very often the cause of a closer slamming the door. But there is no visible indication of a leak in your picture. If it had leaked out, I would expect there to be stains on the very bottom point that is visible in the photo. Instead, it looks clean and perfectly fine.
The bent arm and mounting point on the door are related, I would guess. The installer did a crappy job. At a wild guess, the factory mounting only allowed around 100 degrees of opening, but the users wanted something closer to 180, so things were fudged. Not the end of the world and never the cause of slamming.
The people saying you need to adjust it are likely the ones who have it right. Fortunately for us all, your picture shows what I am quite certain are the adjustment screws/valves. The two screws on the right hand side, sitting parallel to the cylinder. They are both clearly backed out nearly as far as they can go, this would cause slamming 100% of the time. You can even see that the top one is protruding from the surrounding body of the closer.
Turn those clockwise and see if it helps. I'd start at something like 2 complete turns clockwise on both and then test the door. Keep going that way until the door is closing too slowly, then back one off and see if it speeds up. Remember, one controls the speed from full open until nearly closed, so you have to identify which is which by adjusting one at a time, make sense?
Trickle down? It was called VOODOO fucking economics in its day. Plenty of analysts and other people with half a brain understood what a travesty it was and is. BUT too many people at the bottom of the food chain keep getting convinced that it works. :/
What is that retro-looking thing on the right?
Hurst "Lightning Rods" from the 80s. Basically a flashy way to manually shift an automatic transmission.
Good write up and explanation here: https://www.macsmotorcitygarage.com/a-cool-idea-at-the-time-the-hurst-lightning-rods-shifter/