Mechanics Share The Absolute Dumbest Reasons Cars Needed To Be Fixed

Too Much Over-Inflation

Not everyone has what it takes to be a mechanic; otherwise, there would be no need for them. But there are things that all car owners should know and be able to do by themselves. Whether that’s changing windshield wipers, replacing wiper fluid, or simply popping the trunk, people should be able to do a couple basic things with their cars besides drive. Or at least, you would think so.

Of course, people are people, and that means you always have the potential for a few less-than-stellar examples of humanity’s intelligence. Mechanics and car gurus have taken some time out of their days to share the absolute silliest reasons they’ve had to fix someone’s car. Have you ever been to the mechanic for issues like these?

I’m not a mechanic, but a former service writer. A woman came in for an oil change; it’s some common minivan, nothing out of the ordinary. I walked by the van while it was up on the rack and noticed one of the tires was nearly bald in the middle, cords showing. Textbook over-inflation.

The Oil Is Low

I checked the tire pressure, and it was well over-inflated. Then I looked around the vehicle; two more tires were in exactly the same state, over-inflated and showing damage from it. The fourth was a bit under-inflated, with no glaringly obvious tread wear. I pointed it out to the customer when she came back and asked if there’s any reason three tires would be over-inflated.

Long story short, she was occasionally seeing a ‘low tire’ light on the dash (no indication of which tire, just ‘low tire’), told her husband, and he just aired up all four tires. Happened again, ‘fixed’ the same way, rinse and repeat. So over time, they kept the tire with the leak going but managed to ruin the other three. Reddit user:  neightwulf

My old mechanic had a guy come in with a Ford Probe. He claimed it was “low” on oil.  They took the dipstick out, and the whole stick had oil on it. He checked again with the same result. The guy took the oil cap off and looked down into the hole and said, “See, it is low” (because of the word “LO” down there).

Is It Oil or Glue?

He had put 3-4 CASES of oil in the motor trying to fill the entire block up. After he got over the shock, the mechanic advised the driver not to do it again. Reddit user: Chum731

I worked as a car cleaner at a dealership one summer in high school. The guy towed in a relatively new top-of-the-line Corvette he bought there sometime before I started. He was angry that it died on the road and was running just as badly shortly before that.

A DIY Performance Mod

He was ranting and raving about how he spent all this money and it only went X months/years before completely breaking down. One of my work buddies got it up on a lift and started looking it over. He opened the oil drain plug and absolutely nothing came out. Like not even a drop.

He pulled apart the engine, and the oil could be best described as glue. The owner talked to the guy and asked when the last time he changed the oil was. The guy had zero idea what he was talking about; he had no idea that you had to do that. He assumed you just added gas and that’s the only thing you needed to do.

The engine was a complete loss, which meant the car was a complete loss to him. On the bright side, he did stop complaining, especially since he realized it was all his fault. Reddit user: Zebov3

I was working at a performance shop at the time. A Golf GTI comes in for lack of power, throwing check engine codes for under boost and several for fuel trim management conditions. I did the typical process of checking the turbo waste gate operation, pressure and smoke tested the charged side of the turbo system for leaks, tested fuel pressures…it all checked out.

The Problem with Bald Tires

I removed the intake side from the turbo to inspect for rips in the rubber boot; all good. Then I looked inside the intake boot, and this guy bought one of these ‘turbo-nator’ gimmicky things and put it inside the intake.  It had turned completely on its side and was restricting ~80% of the air flow.

I then removed the ‘obstruction’; motor operating values returned to normal, and power was restored. I did not feel any guilt that this dude had to pay a few hundred dollars for me to diagnose and remove his awesome DIY performance mod. Reddit user: robbins549

I work as a mechanic, and I once had a guy show up at a tire shop bragging about being drunk and needing his tire changed. He had his spare on with 3/5 lug nuts. He had tightened them by hand (yes, he did it manually, with no tools) and they backed off. So I had to replace all the studs.

Different-Sized Rims

Folks would come in asking for tire repairs (patches) on tires that were LITERALLY cut in half. Like you drove on the rim for a week, split down the middle “in half.” They’d get so offended when I explained that they not only needed a tire, but now a rim as well. Reddit user: [redacted]

I did a co-op at a shop back in high school. A guy came in and complained about how his car doesn’t sit straight.  We pulled it in and didn’t even need to put it on the lift to realize that he had 17-inch rims on one side and 15s on the other.

Brakes and Oil

It took me about 45 minutes of explaining to him why cars aren’t made like that before he told us that he’d be taking his business elsewhere. On a side note: the tires with the 15s were 100% bald, like racing slick bald, and everything in that car was falling to pieces. Reddit user: lsmrzz

I’m not a mechanic but a car enthusiast.  I saw a couple of cars where owners didn’t know what basic maintenance was. Like no oil change, no brake pad change. The oil turned into jelly, and you had to scrape it out.  The most ridiculous thing was always the brakes.

Diamond Plate Guy and Focus Bro

My mechanic friend showed me the brakes of an elderly lady’s car. The brake discs were gone, like almost completely wiped down to like 5-6 mm. She said to him, “The car feels weird when I brake.” Reddit user: Gregorinio

Let me tell you about diamond plate guy and Focus bro. Diamond plate guy had two things he used to modify his truck: a drill and a ton of diamond plate. It was an absolute base model V6 Ram 1500 with the exhaust chopped off, which I thought was bad enough until I opened the hood.

A Tar Problem

He had drilled or glued diamond plate to EVERY flat surface. Air filter box, intake manifold, fan shroud, etc. And yes, they seemed to be real, genuine stones. This was 18 months ago. My eyes still haven’t recovered, but this isn’t the end. He had some crappy wheels that he had painted white himself.

I think he said he wanted everything to be white and shiny, tires included. I know this because he painted the inside of the wheels where they seat to the hub, which caused them to seize to said hubs. I literally had to buy a bigger hammer to smack them off.

Focus bro is a guy who had a custom straight pipe, full Sparco race seats, five-point racing harnesses, lowering springs, and…a base model, automatic Ford Focus SE. Reddit user: DaJohnDude

My favorite was a customer who came in one day and blew up over this yellow stain on her windshield right over the left side of the steering wheel. We cleaned the windshield, checked the coolant, checked the heater core; we could find nothing. A few weeks later, she was back and angry.

A Long List of Faux Pas

I checked everything we could and nothing, so I sent her on her way.  Next time she pulled up, I walked out, and she said the spot is back. I then figured out that the lady smoked like a freight train and always held her cigarette in her left hand, right next to the windshield. It was tar. Reddit user: Danobing

The list is long of dumb moves I’ve seen. Removing PVC hoses, assorted vacuum lines, the O2 sensor, etc. thinking they were going to get better performance. Cutting a wire under the dash to hook up a stereo. Then bringing the car to me to fix just the tail lights. This was all from one person.

A Few Loose Nuts

He then poured 3 quarts of oil in, but the dipstick still showed low because he put the oil in the radiator. Then he put gasoline in a diesel truck…again. Reddit user: Missanonna

I’m not a mechanic, but while sitting in the shop waiting for my own car to have work completed, I witnessed a customer and their mechanic talking about the customer’s car needing suspension repair. The customer had tried (unsuccessfully) to do the repair himself, so the mechanic asked him why some lug nuts were missing and others were loose.

In the Bro-Truck Business

The customer replied how he thought he would be helping the mechanic by “loosening the tire” for him. The customer had driven 20 minutes to get to the shop with a tire held on by a few loose lug nuts. Reddit user: idonthavefleas

The worst I’ve seen is when dudes spend thousands of dollars modifying their pickups for off-roading, even though they spend 99.99% of the time on highways and the furthest off of a road they ever get is a logging road that a stock Forester could tackle with no problems.

Trying to Cut Costs

And then they want to complain about extra bad fuel mileage and “having” to pay for new 35-inch knobby tires that only last 10k miles because they wear out super quickly if you drive mostly on pavement.  Then there’s having to replace their front wheel bearings every other year because those larger wheels and tires are a lot heavier than the stock ones.

And let’s not forget being super surprised to learn that parts for a 3/4 ton pickup can cost multiple times more than the comparable ones for the small sedan they sold to afford their bro-truck. Reddit user: Clintman

The dumbest thing I’ve seen, hands down, was a customer who came in with a lifted Crown Vic so he could roll around on 30-inch rims. Instead of spending the money on a fabricated kit to do it, he shoved blocks of wood between the spring coils so they couldn’t compress.

Water Everywhere!

The kicker is that he thought he knew what he was doing, and he brought that cocky attitude into my shop when he came in. He humbled up super quickly though, and I told him to never do it again. Reddit user: wdavisb

I’m a tractor mechanic. Once, I got a call from a guy I’ve done work for before saying the auger tractor won’t start after having sat outside overnight. Not so out of the ordinary, but I’m a tad suspicious, so I load up my tools and head over to his place.

Stupid Things Every Day

The first thing I notice is that the exhaust pipe has no rain cap, and it had just rained…a lot. I check the basics quick first: points and plugs (gas tractor) plus battery charge, and then I get to the carb. I open up the drain valve of the carburetor and there it is: a big rush of water.

I drain the carb, thinking that has to be all of it. I clean things up and try to fire it up. It pops off a few times and smokes like a train. Concerned, I tear into things further and find water in the gas tank, water in the oil pan…the entire engine was filled with water!

All of this could have been avoided by cutting a pop bottle and putting it over the pipe. He didn’t seem to be paying attention when I told him how to prevent this from happening. If it does again, I’ll take my time in going to fix it. Reddit user: wdhalbur

I worked at a Chevy dealer and now work at a Jaguar/Land Rover dealer. I’m not surprised at people’s stupidity anymore. More than once, I’ve seen people add oil to the coolant reservoir. I’ve seen the inside of a motor where the customer never changed the oil since it was new and the car had 50k miles on it.

Starving for Air

The dumbest thing I see every day is people who come in with broke suspension parts, bald tires, and no brakes. They don’t buy any of it and just want the oil change and insist we are trying to rip them off. But the same person will come in raising a ruckus over a small safety recall and refuse to leave until it’s done because the car’s “unsafe.” Reddit user: S10_Burner

A guy comes in with a Kia Soul for an oil change and mentions that when he tries to pass people on the highway, the engine bogs down. Now he doesn’t want to pay for diagnostic, so I just say we’ll see if the visual check included in the oil change brings anything up.

The Friend With the Chockola Can

This guy put some aftermarket “turbo” kit in that was just a big fan attached to his throttle body. When he was at WOT (Wide Open Throttle, when the gas pedal is to the floor), it would close the circuit, and the fan would blast air into his engine…only he wired it backward. The fan would turn on, spin the wrong way, and the engine would starve for air. Reddit user: Relmert

A long time ago, the muffler of a friend’s car developed a hole. Her husband split a Chockola can and duct-taped it over the muffler. She later had to have some other work done and was going to go to the same repair man I used. Not only was this man an expert; he was an ex stock car racer.

The $30k Flat Tire

He always had the greatest bunch of cronies around, but they did not suffer fools. At all. I had heard some of their stories and had an idea what they would say if she drove in with that Chockola can. I pleaded with her for days to get rid of it, but she did not.

I had to take my car in for service a week later, and man were there comments. I passed them along, but she and her husband didn’t see the humor. For years later, she was always referred to as my friend with the Chockola can. Reddit user: OldestCrone

I’m not a mechanic, but I toured a car dealership with my school for career day a little while ago. A woman got a flat tire but kept driving for a long time, and the tire was fully severed. It got caught in the wheel arch of this poor Q7 and tore half the wiring harness out.

The Internal Work Made No Sense

The mechanic at the dealership said that the bill was going to be close to 30k. Looking at it, I was surprised it wasn’t totaled. She was more concerned about the bill than possibly causing the deaths of other people. Reddit user: WereMadAgain

I’m not a mechanic but a parts runner.  I have seen pimped up cars that should not run and others that look like a manor on wheels. One of the dumbest was the classic pimpmobile. A 2010 Jeep Grand Cherokee, neon purple, fake leopard upholstery, steering wheel was supposed to look like golden chains, and the internal work made no sense.

Oil Problems

They needed brakes and wheel wells, but the mechanics working on it were laughing every time they went near it. By the end, I had to deliver brakes, a new wheel well, a battery, axels, and an engine block. Reddit user: Eleventh_Legion

I once had a mechanic friend of mine tell me one customer didn’t know that the oil would need to be replaced every few thousand miles and stuff. They just assumed that the maintenance minder was to remind them to check the levels and look under their car to make sure it wasn’t leaking.

The Warranty Doesn’t Cover Idiocy

They thought that all the oil for people to buy was because either the oil would leak or “evaporate” out of the engine. To say my friend was shocked when he saw the state of the oil is an understatement. Reddit user: Autski

I have a number of good stories. My favorite is the guy who poured not one but two 2.5-gallon containers of diesel exhaust fluid into his fuel tank. He just saw the word “diesel” on the can and thought that was what it was for. It crystalized in his fuel system, so I had to replace every component and flush the lines and tank.

Gas in the Engine Block

It was a company truck that was still under warranty, but the factory doesn’t cover idiocy. Needless to say, the company’s owner was not happy about the $3500 repair just because his employee was careless. From what I heard, not only did they take the car from him, but they also put him on probation for a while. Reddit user: wdavisb

I’m not sure if this really counts, because I’m definitely not a mechanic. But when I was working with rental cars, I got a few really dumb customers doing stupid things to their cars. The most memorable was the guy complaining we charged him for repairs and towing after he poured gasoline inside the engine block.

Motor Oil Mistakes to Marriage

He didn’t think he should have to pay for it because he was like, “Hey, I opened the hood and poured gasoline into it, but I have a flight to catch and don’t have time to deal with it, so I’m leaving the car at [location].” He got a rude awakening when we charged his card for his mistake. Reddit user: Karaethon22

I once had a car come in with the complaint of a rattle in the engine and that the car would not shift out of first gear (automatic transmission). They stated that they had just performed an oil change at home and that it was her first time doing so.

All for the Monkey

I get under the hood and check the engine oil level. Bone dry. I fill it up with oil, but I take it for a drive, and it still will not shift. I check the transmission fluid level, and it is practically up to the end of the fill tube, full of trans fluid…and a mix that suspiciously smells like motor oil.

She had drained all the oil out of her engine and put 5 quarts of motor oil into the transmission. She was all embarrassed, but we all had a good laugh. She was really cute too. I got her number. We’re going on 5 years married now. Reddit user: theburningogre

I knew a guy one day who got in a car crash, saying there was something that made him pass out. So I pop the hood, and there’s nothing wrong with the engine. The bottom of the car was somewhat intact after repairs were made by insurance. I was determined to find the problem, though.

Water from a Garden Hose

For no reason, I asked, “Hey, did you attempt to make any adjustments or modifications to your car for any reason?” And he responded saying that he had recently plugged the exhaust pipe with a banana and that he had kept it there with superglue in order to bring a monkey home for his kid.

I told him that because he plugged his exhaust pipe with a banana, the carbon emissions weren’t going into the atmosphere and instead were going into his car, making him pass out, and that it was a miracle that he didn’t suffocate. This was in 1997 when I moved to India for 4 years. Reddit user: Nova-The-Dog

I was a car tech in college. We had a car come in on a tow truck one time because the owner had gotten a warning light on the dash and ended up filling her crankcase with water from the garden hose. The worst part was that the tow truck driver had started the engine long enough to pull it onto the flatbed.

Dropped on the Head

We got it on the lift and pulled the drain plug, and no less than 3 gallons of water poured out, followed by a concoction that looked very much like chocolate mousse from where the oil and water had “mixed.” Reddit user: tacoman1287

My dad’s a mechanic, so I frequently hang out at his workshop and have many stories. I don’t pay much attention most days; busy working on school, reading, or whatever. I do remember a very silly case where some guy was messing around with the motor to ‘stylize it,’ painting it black.

Custom Dual Mufflers

That led to a whole host of issues because he couldn’t even be bothered to paint it properly, so there were just clumps of dried up black paint everywhere under the hood.  My dad had this “did your parents drop you on the head when you were a child?” look that he reserves only for the stupidest of people.

I’ve thus far counted that he made it five times that day while repairing the car (which involved replacing a multitude of pieces that cost the guy a fortune). I seriously hope he learned after that. Reddit user: _Mens_Rights_Matter_

My kid had a Suburban come into the shop for a gas leak (like it was pouring gas, not dripping). Once they got underneath it, they found that most of the vehicle’s exhaust system was replaced with plumbing-grade PVC pipe that was warped and looked like it had caught fire at least once.

Because Diesel Is Better

In addition, all of the body mounts were either gone or nearly gone, so the body was basically “floating” on the frame. It was one of the weirdest things we’d ever seen. Getting the man to understand how dangerous it was was one of the longest conversations we’ve had with a customer.

We also had another car towed in during the winter with the complaint that it would run for a few seconds, then sputter and die. It was left in the shop overnight, and the next morning, it started up just fine. I couldn’t find an issue with it and returned it to the customer.

That night, it gets towed in again for the same thing. After more investigation, we discover a “custom” (using the term very loosely) dual exhaust that had no water drain in the muffler, so the condensation in the exhaust would gather and freeze solid, blocking the exhaust. We had to drill and drain about a gallon and a half of water from both mufflers. Reddit user: Roll3d6

I had a lady complain her car wasn’t running right after she filled it up. I thought maybe she got bad gas like water or something. Come to find out she put a full tank of diesel in it by accident. Her car was meant to take gasoline, but she thought diesel would be better for it.

Customers and Their “Problems”

I also had a man call up and say, “I was driving and a light came on that says check engine. I’m on the side of the road with the hood open, and everything looks fine.” This was a plow truck, and the guy filled up the tank, but the brackets were so rotted that one of them snapped.

Instead of calling a tow truck, he tried to tie it back up to keep plowing because one bracket was still present. Nonetheless, the tank ripped out and took everything with it. Reddit user: Hellionhellion

I worked for Honda as a grease monkey. I ported cars and took customers’ cars to various shops around town, and sometimes, I would take a car from GA and drive to NC. This one guy had a brand new minivan. He used the dark green side of a kitchen sponge on his car. He noticed the “soap” wasn’t coming off after spraying down the van.

A Quick Fix

Another customer came in for an oil change, and we had to check underneath to upsell stuff. The passenger’s front CV boot was destroyed, along with the joint and axle. I got my service manager; he brought the customer in and showed them. A customer said he just needed it for another month.

We couldn’t let him leave because it was a safety hazard. The dude was angry. He had to get his mom to pick him up, and she lived like three hours away. The entire time, he’s complaining and moaning, telling us to burn the car to the ground. We messed up his life. Reddit user: Rootbeer48

Some old jerk tried working on his pickup truck but couldn’t fix it, so he brought it to me, saying it wouldn’t idle and didn’t run right. I went for a test drive, and about a mile or two down the road, I hear this big bang, then the truck shuts off.

Just Hand Over the Keys

I get out and look for the issue and see something shiny sitting on top of the engine. It was a 30.06 rifle bullet, unfired, plugging a vacuum line. I look around more and find another shell casing from one right under a dent in the hood. The dent was going out, though.

The old geezer had plugged a loose line with a live bullet, and it cooked off on top of the engine from the heat from the exhaust manifold. I wanted to shout at that old dude when I realized what he had done. Idiot almost cost me my life with that dumb fix. Reddit user: shotstraight

A friend of mine was the manager of a local auto shop and told me this story. A guy walks in needing to replace the CV joint in the front end of his minivan. After seeing the quote, he flips out, storms out, gets in his minivan, and tries to peel out of the parking lot.

Driving When Wet…

As he does this, the CV joint lets go, thrashing around under his hood. Imagine a solid steel baseball bat attached to an engine revving at full speed. This causes an amazing amount of damage and makes the minivan undriveable. The man walks back in, and, without saying a word, hands over the keys. Reddit user: olbaidiablo

A guy decided it was a good idea to take his new SLK down a dirt road after several days of heavy rainfall to visit his horses that are kept at a rural farm. The car had to be towed to the dealership after being half-submerged in mud. The guy didn’t learn and did it again less than a month later.

Making the Fifth Lug

Except after making it through deep mud, he drove into wet cement where they started to pave the road. The insurance totaled the car after that. Reddit user: skale42

A guy wanted to put five-lug wheels on his early ’60s Ranchero. 1960s Fords with 6 cylinder engines up through 1968 generally only had four lug nuts holding each wheel on. The correct way to do that swap is to put different axles or a different rear end in the car.

Too Much Pressure

The incorrect way, which was so brilliantly embraced, was drilling new holes in the brake drums and axle shafts. Oh, and they weren’t centered. I have a picture somewhere. That’s just about the most dangerous thing I’ve ever seen on a car. Reddit user: MillionSuns

My boyfriend is a mechanic and told me to tell this story. A guy came in with an Audi A8, and his concern was that he had a “rough ride.” The car was vibrating while driving or whatever. The tire pressure light was on, so my boyfriend checked the tire pressure, and they were all at 140 PSI (supposed to be at 36 PSI).

A Custom Pulley System

The tires had so much pressure in them that they tore the internal structure of the tire, which made them lopsided (hence the “rough ride”). When they asked the guy what was up with the tires, he said that his tire pressure light wouldn’t go off, so he just kept adding air, figuring that the light at some point would just go away.

It obviously did not, and he needed all new tires. Some people should just not be allowed to own vehicles. Reddit user: rachelsays_part2

I was working at Sears Auto Center one summer, and we had this guy pull into the parking lot with an early ’80s Ford Econoline…literally the most raggedy vehicle I’ve ever seen in my life. A guy comes in, doesn’t speak a word of English, but somehow manages to convince the CSR that he needs one tire.

Rerouting the Brakes

They get all the paperwork done, and I grab the keys to pull it in. I open the door and immediately realize that something is missing: the driver’s seat. This guy was driving around sitting on a milk crate. It gets worse. There was no brake pedal, and the guy had rigged up a makeshift handbrake, which involved a rope and pulley. You had to give the rope a good hard pull to engage the brakes.

Immediately got right back out of the van, tossed the keys to the owner, and told the manager and CSR what happened. That was the biggest confusing moment I had. Reddit user: txoutlaw89

A guy I knew from high school stopped by to show me how he had “fixed the brakes” on his Integra. He had trouble bleeding the brakes after changing pads (probably not super necessary), so he had completely removed the ABS pump and re-plumbed the brake system in his own special way.

Washing the Engine

He routed the front circuit brake line to one front caliper (removed the Y) and the rear circuit to the other front caliper. No rear brakes connected at all, and one side was getting brake pressure biased to be the rear brakes. I was terrified that he was driving it and that he thought what he’d done was a good thing. Reddit user: jimmyhoffa_141

A woman comes into the shop and says her car doesn’t work anymore. She had the vehicle towed in. Boss sends me to talk to her and get some information. I ask the basic “when did it stop working?” sort of questions. Her reply makes me raise an eyebrow. “After I washed the engine last night after work.”

A Matching Pair of Taillights

I ask how she washed the engine. She says she opened the little cap on the top and stuck a hose inside the top on the engine to wash the interior. When I told my boss, he laughed so hard. I had to tell her she’d need a new engine or a new car.

I get the car on the lift and remove the drain plug, and an entire 5 liters of water comes out with the oil. I had to fight to keep my face straight as she watched. Reddit user: Hobbes1138

Not a mechanic, but my husband used to be. He said one time he saw a teenage girl come in with her very angry mother. The girl had a broken taillight, so she broke the other one so it’d be symmetrical and hoped her parents wouldn’t realize there was an issue.

Pay a Professional

She had come in a week earlier for an oil change, and the woman called my husband and his coworkers some bad names because the daughter realized she messed up and lied that the mechanics did it. My husband said she was really embarrassed but didn’t come clean until after the words were thrown around.

After that, the mom acted like it was nothing and asked how much to have it fixed, totally not seeing an issue in her behavior at all. Reddit user: skinwalkerspotting

I’m a motorcycle mechanic. I had a customer decide he was too smart to pay us to do his oil change, so he bought the oil and filter and did it himself. He couldn’t figure out why the bike kept going slower and slower no matter how much throttle he gave it.

He didn’t put any oil back in the bike, so the engine seized. He ordered a new S&S engine from us. Clearly, he was capable of doing this job himself, based on his earlier performance. We saw that bike three more times after that. Every time this guy did something, he had to bring us the bike to fix.

The first go at the engine install, he left out a spacer and the charging rotor took out the stator and almost machined its way through the case. If you don’t know how to do it, pay a professional; it’s a lot cheaper! Reddit user: northernabguy