There's a reason you leave some things to the professionals! These mechanics share the times amateurs absolutely ruined their cars.
So Close Yet So Unbelievably Far

“Once, an owner of a Lincoln Mark VIII replaced his own spark plugs. While he was driving his spark plugs literally blew through the engine before it was hit the inside of the hood. The guy didn’t have tools on him at the time so he left the spark plug out, unplugged the fuel injector to that cylinder then determined he would just drive it the rest of the way home like that. So far so good, right? Technically not wrong. He’s just running on one cylinder short. No biggie!
Well clearly this guy knew more than most and he was doing ok, but then he thought what if a little bit of sand gets sucked in through the open spark plug hole while I’m driving… That could destroy that cylinder, he thought. So he got a rag (that he evidently kept in the trunk for checking fluids) and stuffed it down the cylinder tube (presumably as a filter). Wrong move, sir.
He didn’t get very far. On one of the intake strokes, it sucked the rag into the cylinder which jammed up the system and held one of the valves open. No Bueno.
The piston hit that stuck valve repeatedly until it broke causing some serious damage. The rag got shredded to a fine powder and was ejected mostly out the exhaust where it went through the catalytic converter. But that valve head that went through the piston? Well, it made it into the oil plan which clogged up the oil pickup tube and caused even more problems.
Now keep in mind that once the piston cratered oil was being fed into the exhaust and that’s why we couldn’t get the rag out of the catalytic converter. He heard all the noise but he thought it was just that the rag got blown out and he was just hearing a normal cylinder with the plug removed until the oil light came on.
I felt so bad for him, he was a really nice guy and that motor and cats were not cheap! I wish he had just called for a tow..
I have hundreds of stories that cost less, and a few that cost more, but that one broke my heart!”
Kid Mechanic Gets Away With Possibly Wrecking Transmission

“I was told by her boyfriend to change the oil on his 1967 Dodge camper special pickup truck with an automatic transmission.
It was 1971, I was 14 and had never changed oil by myself before. I’m not sure why he let me do it or why I even agreed to it but hey I was just a stupid teenager. I get all of the tools and whatnot and start draining what I thought was the oil. Except this oil didn’t come out black. It was red, oops. Everybody knows what that means right? Who needs transmission fluid anyways!
Not wanting to get in trouble for making such a monumental mistake, I put the transmission fluid back into the transmission. Through the transmission dipstick tube with a funnel. It’s not as easy as it sounds. This is the first time I have ever mentioned this and hope he isn’t reading this.
He was not a bad guy, at least he was not physically abusive to us kids. She was with him for a few months but luckily I never saw him again with her.
A few years later I saw him when I was 18 and he recognized me. As he was making conversation, he told me he still had the truck but the transmission was slipping. ‘Oh, really now? How about that,’ I said.
I pretended to play stupid but I think I was giving myself away. My face turned hot and red as I tried to keep my cool, wondering if he knew what I did or maybe wanted me to replace the transmission. I mean, hey I was only 18 I knew I didn’t have the money for that.
We talked cars for another moment then I said something like ‘Wow, bummer man’ changed the subject then suddenly remembered that I had a ‘thing’ to get to and excused myself. But boy did I get the heck out of there. Luckily, I never saw that guy again! Phew!”
“I Finished Your Car But You’re Not Able To Drive It Home.”

“I took an immaculate ‘97 Accord that showed serious ownership pride and created, because of my error, a total loss of $10k inside my shop without anything else is damaged. Not my proudest moment! It was a simple job: brake pad change and strut replacement on all four corners. I used two lifts in my shop. I drive the vehicle between the two posts. Each post has two arms that reach out under the vehicle and lift it from the frame mounts. This is a very popular, simple lift used in most shops. I used a muffler stand in assisting the installation of the struts. Muffler stands are about 3-5 feet tall rods with a head-on top used to hold up the muffler while doing exhaust jobs. A very common sight in a shop.
Mid-afternoon, I had accomplished nothing on this job due to customers and phone calls and needed to get the job finished ASAP. I let phone calls go to voice mail and put myself into overdrive. Once the job was completed, I removed my tools and parts from under the vehicle and slid the stand out from under the left rear tire toward the rear of the car. In my haste to finish, I never once double-checked myself, as I trusted my supreme mastery of the task. This act of itself is a prime example of someone smoking his own crack.
So, as I stood next to the driver’s door, lowering the vehicle on the lift, staring out the front of the open bay door deciding what I wanted for dinner, I didn’t have a clue that the left rear corner of the car was not dropping as the rest of the car was coming down. In the end, one inch was all I needed. I failed to confirm the stand I slid toward the rear of the car had cleared the bumper cover. That rear corner was still held up by the stand! NO!
My peripheral vision noticed the driver’s door pitched forward. In a panic, I released the lift‘s switch and nervously watched the car teeter precariously…for about half a second. Then time seemed to move in slow motion as I helplessly watched the car shudder then take a calamitous nosedive. The car slammed into the floor so hard that it bounced and rolled like a pachinko ball between the stands and lift arms. I thought I was dead the crunch was so loud.
‘Oh fudge!’ (Okay, maybe not those exact words…) The bumper cracked, the fender bent. Creases were in the doors. The C pillar looked like a washboard. I thought I was going to hurl. Then my reality sank in, and I truly wished this was a normal customer and not some crazy lunatic.
That evening I had to make one of the worst phone calls ever: ‘Uh, I finished your car…but you’re not able to drive it home.’ The best decision I ever made was having shop insurance, which paid handsomely due to the car’s pristine condition, blessedly allowing a large upgrade in the new vehicle she now needed to replace. But yeah lesson learned! Now I always check every stand when I lower a car from the lift!”
At That Moment He Thought His Life Was Over

“In about 1995 I was repairing a carburetor on a 1985 Toyota pickup truck. A base, no-frills model with a 4-speed stick trans, no a/c, plastic seats, and a 22R engine. A real plain Jane. I took the air cleaner housing off and manually set the auto choke to monitor the pull-off diaphragm when it was first started cold. Back then there wasn’t a clutch safety switch and I didn’t realize that the truck was in gear.
So I was working on the truck but I stupidly forgot that the truck was in gear. I reached in the window after setting the choke and fast idle by hand and turned the key to start it and that’s when I realized my grave mistake.
Well, being in gear, the Toyota took off across my shop in first gear and on fast idle. Uh oh! I grabbed the door handle and opened the door to jump in and stomp the brake pedal. And I did just that. Or so I thought. I was in a panic and with my heart pumping. There was the screeching cacophony of loud noises, and smoke all around me and then I felt something knock me in the head. Hard.
Do you know what hit me in the head? Another friggin’ car! There was a Chrysler Lebaron convertible up on the lift above us and as the Toyota came rolling through it hit the lift it was on! So now the Chrysler was coming tumbling down from the lift as the lift stands started to steadily rip from the floor! I’ll be honest l don’t think I’ve ever been so panicked in my life. I thought I was going to have a heart attack.
After the shock of getting hit in the head with another car I looked down and realized my stupid self had put my foot on the GAS, not the BRAKE. So all that smoke? That was me stomping on the gas and causing a wicked burnout on the shop floor. When the dust had settled I had a nice shiner on my head plus two messed up cars. I thought my life was over.
The truck? Well, it was totaled and about 6 inches shorter than stock. The Chrysler? Well, it was a convertible so we took out the seats and several of us jumped on the floor to flatten the hump that I custom made all by myself. The owner never knew anything happened because it was as good as new after our custom frame and bodywork.
The guy had his truck from day one and absolutely loved it even though it had a gazillion miles on it and looked like it was bombed out with a mortar shell. He was a big biker type ironworker that worked on nuclear plants and I’m freaked that I ruined his truck knowing how much he loved his truck and that I was half his size.
He didn’t have a phone where he stayed so I went to his house and told him the situation while groveling and apologizing profusely. I drove there with a 1987 Toyota with a/c, auto trans, new tires, and a lot fewer miles on it that I purchased from a local dealer I knew. I paid $2500 for it a half hour after the incident and gave it to him. He was in shock and said it was all good. He was still ticked off though, I could sense.
A week later I saw him coming up to my shop and my stomach knotted up fast. He wasn’t smiling. Well, when he came into my office with his wife I thought he was going to stomp me. But, he then asked my if I remembered what I did to his truck. I of course said yes and apologized again. Profusely. He then asked me if I could do the same thing to his wife’s car since they were there to drop it off for an oil change and it was also a lemon. I knew then all was good between us and he’s still a client to this day. Thank God there’s no more carburetors and cars have clutch safety switches these days.”
Always Use Your E-Brake!

“I have always worked on cars as a hobby. One day I met a guy that had recently moved from his hometown, where his ex-wife and daughter lived, and all he had in his life was his VW GTI VR6. It was his pride and joy. I felt sorry for the guy because he had been unemployed for over a year. Lost everything. Had to move several states away to get a good job. When we were talking he had mentioned that he went to a Valvoline and they said he needed new brakes front and rear. I told him to come by my house on Saturday and we could do it in my garage, super easy and it would save him like $400 over what he had quoted to do the job. I was living in an older house but had a big garage leading out to a heavily sloped driveway.
Saturday rolls around and we put the car in the garage I tell him to put the car in first gear and set the parking brake so we can break loose the lug bolts, I jack it up, remove the wheels, disassemble everything, but when we get to the rear rotors I realized the parking brake was still set which wouldn’t let us remove the rotors. He jumped in the car and released the parking brake. No big deal, the car was up on jack stands and had no wheels. we get everything replaced and put the wheels back on, remove the jack stands and go inside to wash up with a job well done.
A minute later there is a knock on the door and it’s the kid from the house across the street and he says ‘Hey mister, your car rolled out of your garage and through our garage.’
My jaw dropped. Oh no. I look outside and sure enough, the VW was literally inside their garage almost like someone had parked it there, except forgot to open the garage door first. So evidently what happened was that when he had gotten in the car to release the brake, he also put the car in neutral because he thought it needed to be, even though there is no logical explanation, and we never put the e-brake on. So after we went inside the car started rolling went down the steep driveway and across the street at the perfect angle to miss a fence and then exactly in the middle of the garage door. With the weight and momentum, it ripped the garage door off the tracks and folded it around the car and the car came to a stop right in the middle of the garage.
The guy’s insurance covered everything, the new garage door, his new bumper and rear hatch, window, taillights, and of course repainting the back of the car. The attempt to save $400 ended up costing the guy over $1,000. Yikes.
To make matters worse, a few months later a new family moved into the house with the brand new garage door, and they were evidently cooking crystal in the garage and about 3 am one morning we woke up to the house up in flames, the entire garage burned to the ground.”
A Mistake So Bad He Just Wanted To Hide Under A Rock

“Okay so here goes. In 2005 I’d just got out of prison and was still looking for work. Unlike my past self though I was determined to do the right thing and live the remainder of my life in the free world this time. A friend knowing my intentions let me do some work to her daughter’s Acura. Before going to prison I was employed at a Honda dealership so I know the Hondas and Acuras quite well.
It had been almost five years since I picked up a wrench and I was a bit rusty but I thought I would take a whack at it anyways. So he wanted me to replace all three engine mounts. The rear one I had a difficult time with and had to jack the engine up a lot to install the rear mount. So after spending all day working on the car it had just got dark and a friend who had helped me with the job and I went for a test drive.
After driving the car for about a mile everything seemed fine and the car ran great. So as I was driving the car back to the owner’s house my buddy decided to turn on the stereo. You know the ones the kids like these days with all the amps and the bass that rattles the license plate frames. So as he turns on the stereo I noticed a small flash go off under the hood. I wasn’t sure what it was and continued driving. After about four more blocks suddenly I start to see smoke billowing out from under the hood on the driver’s side.
Uh-oh. My heart sank.
So I freak out and pull over to the curb thinking to myself this isn’t good. I then pulled on the hood release cable only to have the whole lever pretty much fall off in my hand. So now I couldn’t get the hood open. The reason is because the fire that was now burning had melted the hood release cable! Now I’m in panic mode ringing all the neighbor’s doorbells asking if anyone had a fire extinguisher I could use. The problem was I was pretty much covered in grease and if I were in the neighbor’s shoes I myself probably wouldn’t have opened the door either.
So at least one of the neighbors called the fire department. While all my friend and I could do was watch the car go pretty much up in flames. The fire department managed to arrive before the flames made it to the interior of the car but at this point, it was totaled. And if it wasn’t after the fire department was done ripping the hood open and dousing the flames it was a total loss.
Needless to say, calling my friend was a phone call I hated having to make. She answered and in her anticipation, she said: ‘Cool your done with the car how long before you make it to my house so I can pay you?’
Oh boy. After taking a deep breath I told her that I was almost there but can no longer make it. I told her on the way there her car caught on fire and burned to the ground. Her response was, ‘Very funny so when can you be here?’
UGH talking about wanting to crawl under a rock and hide for a year or so. Or heck even put me back in the hole a year as punishment would have felt better. In any case to make matters worse, I asked her to come to where the car was and I’d try to explain what I still really didn’t know how the fire started.
Yes, she was quite surprised to see the car. After the fire department made sure the car was a total loss I felt like a dumb idiot and it took my friend a while to get over it. I had no money but I did get to pay her back by installing head gaskets on a V-8 Dodge truck she had and a few other things. The way I figured it is while lifting the engine I must have stretched one of the power cables going to the amp from the battery exposing the wire which was then laying on metal and once the stereo was turned on poof!”
It’s Okay To Ask For Help!

“I can tell you how much someone else messed my car up. My wife loaned her car to a friend to go 300 miles from our town. While on the way there, the AC compressor seized up so he tried to fix it but only made things so much worse in the process.
If he had called me I would have told them to cut the AC belt since it is separate from the serpentine belt, instead, they bought a new compressor tore everything apart put it back together completely wrong made it about 50 miles before the car blew. Then he had to have it towed the rest of the way. I already had another compressor so I let them take his back, but I on the other hand had the pleasure of replacing both belts, both tensioners as well as the compressor. Oh yeah, he managed to royally mess things up.
Instead of loosening the serpentine belt by using the adjustment bolt on the side, they took the nut off of the pulley and pried the entire thing apart then put it back together which is about as messy as that sounds.
And oh boy. I took a look at the car’s floor pan and lift points then sighed heavily.
The friend decided to jack up the car (no clue why) and mistook the floor plug for a reinforced pad to jack up the car for some reason? I mean yes floor plugs are black and rubber but c’mon. That just don’t make any sense. So yes, this guy lifted the entire weight of the car on a floor plug which went as well as you might think.
So now we had two small holes and a big ole dent in the floor of the car made by the scissor jack from the trunk which had never been used before. This person denied doing it, but didn’t exactly cover their tracks well. I was definitely angry because none of this had to happen, one phone call and cutting the AC belt there would have been no problem. Word to the wise! It’s okay to admit when you’re wrong; you might just save your car in the process!”
Tales From A Ford Tech

“I used to be a Ford tech so we saw some godawful horrible fixes. The top ones that come to mind include some poor guy who filled a diesel modern engine with gasoline then tried to fix the mistake by running the fuel pump with the return line off the tank to pump out the gasoline.
Sadly, for this owner, the moment he turned the ignition the gas had already spread throughout all the injection systems and cylinders. So there was really no way he was going to get all of this out of his system. Oh! And he also voided his warranty that day too. This little mistake cost him eight new injectors, new fuel lines, gas tank, and new fuel filters. All to the dazzling tune of $15,000 dollars!
The second snafu was a truck that was bending pushrods in Mexico. For the uninitiated, the pushrods are attached to the camshaft and get the cylinders pumping.
To get back on the road this DIY mechanic welded the pushrods back together and hammered them flat. Very ingenious roadside fix but pushrods are a bit more sophisticated than that. Pushrods also have a built-in oil channel to keep them nice and lubricated. This poor dude obviously didn’t take that into consideration. His hack job welding didn’t take the oil channels into consideration so his engine seized pretty quickly. So pretty much his cylinders were toast and got compressed into the combustion area.
Diesel engines however are incredibly strong and forgiving. They will keep running while a gas engine would go kaputt. That guy bought an entire engine but he kind of seemed like he expected this to be the result when he welded it up so he wasn’t very upset at the $2,0000 dollar bill.”
From $139 To $6,000 Quick!

“I had a customer that had a clogged radiator. He thought he could flush it himself by just pulling the drain plug and then filling it with water (the radiator clogged up due to never flushing the system and only using water instead of coolant so it was full of rust) water boils a lot faster than coolant so the radiator got too much pressure busted and he overheated the car. He blew the head gasket trying to drive it to the shop and it overheated like a furnace.
Another time a woman came in for service. We told her that coolant was leaking from the thermostat gasket. She didn’t want to pay the $139 for the repair or pay $3 to top off the coolant because she claimed every time she took the car in for a service that we would try to sell her something she didn’t need. The car was severely neglected and she never changed a single filter.
She would only get the oil changed every 6–7K miles only using conventional oil. A few days later she called that her car overheated. I explained to her not to drive it and have it towed to the shop. She showed up a few hours later in the car which seized up just at the entrance to the parking lot at the shop. After driving around all morning she overheated the car, blew the head gasket, and seized the motor. She was upset and claimed it was our fault. She called her brother and luckily her brother had more sense than her and explained that we did warn her about the leak. He also pointed out that we did give her an estimate for the repair that was attached to her original receipt from a few days ago. He also told her about the coolant leaking on the driveway so a $139 repair turned into a $6k repair between new motor and labor.”