When it comes to cars always listen to the professionals. These mechanics share the times they've seen customers do stupid things to their poor vehicles.
Her Car Sounded Like A Rattling Coke Can Full Of Bolts

“I took a few high school auto shop classes so I guess you can call me a mechanic. A co-worker of mine asked me to look at her car as it was making some grinding sounds. The first thing I did was check the oil, saw that it was not even touching the dipstick. So, I told her to add some oil and see if that fixes the problem. The next day she comes to me and says she added oil but now the car won’t start. So, she has the car towed to my house, I look at it and I try to turn it over, the starter is engaging but the engine isn’t turning. I pop the hood and check the oil.
She took my advice of adding oil, but I should have clarified how much to add. She added so much oil that it was practically spilling out of the dipstick tube. Once I drained the oil down to a practical level, I was finally able to get the engine to turn over only to discover that she hydro locked the engine with all that oil and shattered a connecting rod or piston. Sounded like a rattling Coke can full of bolts. I felt bad that this poor girl just destroyed her car because I told her to add some oil.”
He Talked A Big Game For Someone Who Didn’t Know What He Was Doing

“I was just a grease monkey in a tire shop one year while taking care of my grandparents in a small desert town in Washington. The boss left for a week-long vacation and left me in charge. This kid got hired (maybe 19 years old, tops). He was so god freaking obnoxious. He told everybody all of these outlandish stories:
-he used to be on the SWAT team
-he was an ASE certified mechanic
-he just got out of rehab for narcotics
One day, I told him to drain the oil out of the car I was working on. He went downstairs. After a few minutes, he said that the oil was out. I checked the dipstick (the actual dipstick. Not the idiot in the lower bay) and it was still maybe a quarter OVER full. Without saying anything, I went downstairs to check Fuckstick’s handiwork. I guess they never taught him that transmission fluid isn’t the same thing as oil. The kid drained a brand new (at the time) Suburu’s transmission.
Fuming, I stormed upstairs and berated him in front of the whole crew. I told him the only excuse to be that stupid was that somebody must have ‘peed in his mother when she was pregnant with him.’
The kid cried and we all shamed him for being a moron.
I ended up having to call the customer and say there had been a mix-up and that we were going to be replacing the transmission fluid as well at no extra cost. The customer was totally chill and I covered the shop’s butt.
Fast forward to when the boss is back. He quickly exits the boss’s office, who is roaring obscenities and chasing him out. The kid left. When we asked what had happened, he said he had gone to the office to narc me out for being mean. Boss chewed him out because I’d already left a report on his desk explaining the whole situation for him to read when he returned. That was one of my favorite jobs ever. The crew really was like family. We hired some lousy people sometimes, but they never lasted long. Good times.”
Just Another Day At The Office

“I used to do towing and roadside assistance.
I was dispatched to assist a customer with a tire change. I arrive and it looks like the guy had attempted it himself. He tells me ‘Hey man, my jack won’t go high enough so that’s why I called you.’
Okay then. So I head over to take a look. He’s using the factory scissor jack. But instead of placing it on the pinch weld like he was supposed to, he placed it under some random part of the vehicle and had punched a hole through the floor of the family minivan.
I was honestly dumbfounded at this guy. I pulled the jack out of the subframe of the van, put it under the pinch weld, and got those folks on their way. I guess they really didn’t care about the hole in their floor?
Another time there was this moronic lady who was having her son’s Jeep towed to the shop. It kept losing electrical power. She was ranting about how it couldn’t have been her son’s fault and he was a professional when he hooked up the stereo and light bars. She kept trying to get me to take her side (like I even care) that the shop kept doing lousy work and removing her son’s mods and how they were gonna pay to fix it. When I opened the hood I saw an absolutely jumbled mess of wires!
Like okay, imagine the chaos of cords behind your TV…but under the hood of a car. YEAH. It was an absolutely abysmal mess.
I wish I had a picture, but the system was being sapped of so much power because the dumb son just went overboard with the wires. Not to mention all the clutter under the hood was a huge hazard.
Another one of my other favorite customers was honest at least. I got called to tow a really nice 50s Chevy Bel Air. When I show up there are burnout marks in the driveway. Customer’s explanation?
‘Ah well you see I got really plastered last night and started doing burnouts in the driveway to show off to my friends. Then the transmission blew out eventually,’ he said very matter of fact.
Welp. That sucks.
Then there was the dude who tried paying me with a quart-sized sandwich bag full of joints after he had just wrecked his car into a tree on the median. He told me ‘I know how to deal with guys like you,’ and whips out this bag of joints. I declined his offer.
Sorry, bud, cash or credit only. No pun intended.
Also picked up this sketchy-looking couple once. They had to pay $50 in overages for their tow since their roadside plan didn’t completely cover it. The dude says ‘Man, we don’t have $50, but she will blow you the entire way,’ and the girl winks and smiles at me.
Nope, nope, nope. BJs don’t pay my bills. Ended up leaving them since they didn’t have the $50.
That job kinda sucked, but I always came home with a story at the end of my shift.”
He Put A Banana Where?!

In 1997 I lived in India for four years and worked at an auto shop. Not everyone there has a car so the repairs I did there were always kind of goofy Knew a guy one day who got in a car crash saying there was something that made him pass out. So I check pop the hood and find nothing wrong with the engine. Then I jacked up the vehicle to discover that the bottom of the car was intact after repairs were made by insurance. And then for no reason, I happened to ask ‘Hey did you attempt to make any adjustments or modifications to your care by any chance?’
The guy responded saying that he had recently plugged the exhaust pipe with a banana with Super Glue in order to bring a monkey home because his kid wanted one.
YEAH.
I kid you not.
I’m honestly not sure what the thought process was going through this dude’s head. I think he believed that the banana smell coming from the exhaust pipe would attract a monkey? I’m not sure exactly.
I shook my head and told the man that because he plugged his exhaust pipe with a banana the carbon emissions weren’t going into the atmosphere and instead we’re going directly into his car. This was the reason his car was making him pass out and that it was a miracle that he didn’t suffocate. This dude was casually inhaling toxic exhaust and carbon monoxide.
Listen To The Professionals

“I am a former auto service writer.
Had a lady come in wanting her oil checked because she thought it was low. Checked it myself and informed her she was actually full, the oil was clean, and she was all good to go. She wanted proof so I showed her the dip stick but for whatever reason, she didn’t buy that. She wanted to see that the engine was indeed full of oil.
I tried to explain to her that’s not how it works and that it only takes a few quarts for a car her size to be good to go. Even went into detail about how the engine pressurizes itself and the oil is pulled up from the pan into the engine to do its job.
She eventually left though seemingly unconvinced because she couldn’t take off the oil cap and look down into the hole to see oil.
A few hours later she calls the shop mad as can be because she put in a number of quarts more of oil before it was actually full and was on her way down to us in order to show us how to do our jobs.
Tried to inform her that the best option would be for her to pull over but she promptly hung up telling me she would see me shortly.
A few hours later she calls back again trying to say we ruined her car and that the engine blew on the interstate because we didn’t proper fill her engine with oil.
Wasn’t until insurance refused to cover anything because she had overfilled her engine and blew the seals before seizing the engine and shockingly nothing we did.
She would regularly come by the shop for awhile threatening to sue and so forth. When she was eventually contacted by our attorney she stopped coming around.
Not really sure what happened to her after that.”
Guess Who Paid The Tow Bill?

“Service Advisor here. This story happened to me a few months ago.
A customer brings in their car last Wednesday and they say they have a shaking issue. Okay, nothing crazy. This is a fairly common issue. So we take a look and find a bad axle, some wear on the differential, dirty transmission fluid, blown rear chocks, and the vehicle is also needing an oil service. So we give this list of needed work to the customer and they shake their head. We only do the axle and fluid service.
Now let’s fast forward a bit. A few days later I get a phone call from the same customer.
Customer: What in the bloody blazes did you do to my CAR?!
Me: What’s the issue?!
Customer: The issue is back, and it’s 1000x worst now you idiots! What the heck did I pay you for?!
Me: Okay, well if it is our repair that caused the problem we are more than willing to see what’s going on.
Customer: I demand a tow truck to be sent out and you guys HAVE to flip the bill on this, I’m not paying for this nonsense.
Me: Sir, not a problem. If it is work we’ve completed then we are happy to pay for the tow and correct the issues. But be advised, if the issue is due to the OTHER recommendations or new issue, you will be responsible for the tow fee.
Customer: Yeah that’s fine, I know it’s what you guys did anyway.
Me: Okay. Well, the tow truck will be there within the hour, sir.
We hang up and end the call.
So, the tow truck comes to pick up the customer’s vehicle and brings it back to our shop. But before he picks it up, he makes the customer sign a waiver stating that he is aware of the damages to his vehicle.
The first thing I notice wrong with the vehicle is obvious: IT HAS A FLAT TIRE.
Well, no wonder the guy said it was still shaking. This idiot had been driving with a flat tire. Plain as day, there is a puncture on the right front tire. The tire has a nice gash on the sidewall and I can tell that the idiot had been driving his vehicle on the flat tire for days because there is damage to the rim as well.
‘Well then…’ I say to the customer. ‘Sir, you had a flat tire, and you were obviously driving on it.’
‘Nope, not possible!’ the customer pleads, ‘My car left here completely fine! I’ve barely been driving it and it’s been sitting in the driveway all week!’
‘According to the receipt, you acknowledge the puncture WITH the tow truck driver and signed off knowing it was flat. But we did install the spare, drove about 10 miles on the street and highway, and we were unable to replicate the issue,’ I say.
The customer simply grumbled as he pulled out the waiver to reread it and spotted his signature right on the dotted line.
Guess who just paid 75.00 on a tow bill.”
One Decimal Point Can’t Make A World Of Difference

“About 20 years ago, I worked in an oil change shop in Northern Illinois. This one day, this red Camaro pulls up with some Florida plates on it. The woman gets out of the car and says she’s passing through town on her way to Milwaukee and that the engine ‘kind of has a knock to it, and it’s not accelerating very quickly. I’m hoping it just needs an oil change.’
So I start the pre-oil change service (filling washer fluids, checking brake fluid, power steering, etc.) and decided to pull the dipstick just to see how the oil looks. Nothing on the dipstick. I wonder if maybe her car maybe has a leak.
I pull the car onto the lift, and man is that engine not running right. So I raise the car to start service, and everything underneath looks absolutely pristine. No sign of any leaks. I’m noticing that the oil filter looks like the factory filter. Now, the car has like 25,000 miles on it so I assumed she’d just been taking it to the dealership for services.
Then I opened the drain plug. Anyone who’s ever worked in an oil change shop knows that the oil in a brand new car is a heavier weighted oil with a kind of green/brown color. So that’s what I’m seeing. I put a finger into the flow to look a little more closely at the oil in the light. Sure enough, it’s factory oil. Not only was it factory oil, but there are enough little metal shavings in it that it may as well have been glitter-oil.
So I go show the woman, and say ‘Well, part of the problem is that you for sure didn’t have enough oil in it. The other problem is that whoever did your last oil change put in the heavy grade factory oil. You really don’t want that in your engine any more than 3,000 miles.’
She looks shocked, and says to me ‘This is going to be this car’s first oil change. I didn’t know you’re supposed to change it so soon after you buy it!’
So yeah. Woman goes out and spends $45,000 on a car and has no idea you’re supposed to change the oil EVERY 3,000 miles, not once every 30,000 miles!
I know that after I finished the service and pulled it out of the shop, it seemed to be running a lot better, but I have no idea whatever came of that car or that woman.”
This Guy Has Seen It All

“Oh, boy do I have a long list of stories.
I remember one situation involving two different vehicles — one 1-ton pickup, one solar power system in an RV — wire up their twin 12V batteries in series, frying several parts of the 12V electrical system with 24V, including the second battery.
Then there’s the young girl who poured motor oil into her brake fluid reservoir of her Cobalt thinking that’s where engine oil went in to top it off. It had been in there long enough to ruin just about every piece of rubber in the system, so basically, everything was contaminated to the point of needing to be replaced. She probably got rid of the car, I have to imagine a written estimate would have been at least half the value of the car at the time.
The time a customer had his buddy flat tow him in by tying his Ranger up behind a Jeep with a big ole’ length of rope for several miles was amusing and highly dangerous/illegal. They were very clearly impaired. He had tried changing his spark plugs (not the only thing it needed) and managed to completely strip out the cylinder head on one plug. Then he blamed us when this basket case of an engine ran like trash when all we did was manage to get it to run at all.
Let’s see, 20k miles on conventional oil sludging up the engine, absolutely no end to dangerous tire stupidity, including bearing witness to a rollover/3-vehicle collision caused by someone else installing illegal tires on an F-250 which we refused to the very same customer mere days before…
A customer comes in with an Accord, complaining her son seemed to have done something to make it louder. We get it up on the lift and… well, he had taken a Sawzall to remove a 6-inch section of pipe and used hose clamps and a metal bar to keep the two sections attached to each other but completely open to the air. She got the bill, he lost all driving privileges.
Oooh! One guy had a beat-up Elva (obscure vintage English sports car) with residential wiring and plumbing fixes throughout. That is to say, brazed copper pipes in the cooling system with a homebrew twin(!) radiator setup (which still overheated), and actual residential wire and twist caps (which still didn’t work). He wanted us to get it running again for hooning about in a field. That would have required undoing literally everything he had ever done to the car, and a lot more. It left on the trailer it came in on. Shame, the Elva was literally a street-legal track car of its time.
Oh, you did mean today? Dodge Dart, uses wheel bolts instead of studs. Cheap aftermarket wheels with incorrect spacing, no hub-centric adapter rings, has cheap ‘universal’ wheel spacers to clear the front brake calipers. Neither the wheel spacers nor the wheels were intended for use in this application with wheel bolts. The spacer has no way of centering on anything, so trying to sandwich it between the hub and the wheel while entirely supporting the wheel in the air and threading in the wheel bolts one can’t help but let it slip crooked — which is what the customer did when he put them on himself, which caused it to scrape the brake caliper bracket. It was a juggling act to get it centered enough not to interfere with anything. But those wheel bolts are still being subjected to a lot of additional forces that hub and wheel assembly was never designed for, and at some point, something is going to fail. Also, the front tires were brand new. Rear tires were old, worn, and very dangerously low on air — basically flat.
Never install two new tires on the front with old, worn tires in the back. This is dangerous in bad weather, especially in the winter. If the back end suddenly let’s go first, I don’t care how good you think you are, you aren’t recovering when the front has so much extra traction and the rear has none. The front tires act as a pivot and send you spinning out of control, the back tires can’t regain enough traction to straighten back out. But if the front end lets go first, the newer rear tires can still slow the car down in a straight line long enough for the front tires to regain traction for a safer stop. If you have four matching tires of equal wear and grip, it’s much easier and more predictable to recover from a sudden loss in traction. Conventional wisdom is really wrong when it suggests putting new tires in the front.
Michelin did a lot of testing with it, and it’s our corporate policy to put them in the back for that reason. Same for winter tires, never install just a pair on the front of a front- or all-wheel drive vehicle with all-seasons in the back. We only install in sets of four winter tires, with the modestly better-mismatched pair going in the back if they aren’t all four the same.”
This Guy Managed To Mess Up Twice In The Same Day

“Two friends and me (well, one friend and an acquaintance of him) had a thing going where we’d pool our money and buy camper vans, restore them and sell them. Or buy them abroad, drive them back home, get all the paperwork done, and sell for profit. It was a decent gig, I mainly like to because of the road trips abroad and getting to work on camper vans while making a few bucks besides my normal job.
The acquaintance of my friend was a nice man. He had money, didn’t really need to make more but was in it for the same reasons I was. I’m pretty handy around cars, engines, and motorbikes, my friend is a god dang genius with them and I assumed the third dude would be somewhere in between my friend and I, skill-wise.
Boy, was I wrong?
We found a van we liked and contacted the seller, it was abroad (France, we’re in the Netherlands) and both my friend and I were unable to go pick it up. The other guy had some business to do in France (he owns several companies and is always up to something) and said he’d pick it up and drive it back. We gave him our cut of the money and on he went.
Sure enough, my friend gets a call. The van broke down, reason? The dude put diesel in the water tank. My friend told him it’s fine, we’ll have to clean out/possibly replace the water system, just get it to a gas station and put diesel in the diesel tank. Don’t worry about the water tank, for now, just get it home.
The friend gets another call. Van broke down again. Turned out the dude didn’t put diesel, but gasoline in the diesel tank. “I thought you said gasoline though!”. We were unable to help him out and basically told him to sort it out. He managed to arrange transport and get the dang thing back to us, which is when we really started doubting his ability to think. Not only is it very obviously a diesel van, the cap of the water tank DOES NOT look anything like a gas tank, it also has W A T E R written right above it bright red (van was white). Same for the diesel tank, which did look like a gas tank, and had D I E S E L spelled above it.
Then we checked the water tank to see what he put in there. Because when he called us, he clearly said he’d put diesel in the water tank. He got some out… it was obviously diesel.”
It’s Always A College Kid

“About once a month we’ll get a diesel in that somebody filled up with unleaded. Once we had a customer who put diesel in her Ford Fusion, which is much more impressive. Diesel pump nozzles are bigger, to prevent exactly this. Undeterred, she got a funnel and used it to slowly fill her tank from the diesel pump.
But by far the dumbest thing I’ve ever seen was on an early 2000’s VW Passat brought in by a college kid (it’s always a college kid). I’m handed a work order that says simply ‘running rough.’
Go start the car and it’s misfiring terribly, gotta keep the pedal nearly floored just to limp it into the shop. Open the hood and there’s oil everywhere. Pull the dipstick and oil starts bubbling out of the dipstick tube. Raise the car and pull the drain plug, and somewhere between THREE TO FOUR GALLONS of oil drains out (engine capacity is something like 5.5 quarts).
Sweet Jesus.
Did this guy try to DIY his last couple of oil changes and just skipped the part where you drain the old oil out?
Nope.
The story I got later was that the dude had noticed an oil spot on the ground and figured he had an oil leak. So far, so good, but not for long. Figuring it would be easier to find the source of the leak if there was more oil in the engine, he says he proceeded to add oil until it was full. My service writer asked him to clarify, and he said he kept adding until it was up to the opening where you pour it in!
And the poor thing actually ran that way for about half a day before it started misfiring!
Half a case of foaming degreaser later, I put in the prescribed 5.5 quarts and start it up expecting oil to start pouring out of the front and/or rear main seals, but by some miracle they held! We advised a new set of plugs and valve cover gaskets, and that he drive it a few days and bring it back so we can try to spot the original leak, now that it’s been degreased.
He declines everything, pays for his oil change, and leaves. Two months later he’s back saying his check engine light came back on the day after his last visit and now it’s running rough again. Misfire and PCV system codes are no surprise, so I again recommend spark plugs and valve cover gaskets. If he’s the luckiest fool ever that will be all he needs. He again declines but asks us to clear the codes. And happily pays $50 for a code scan and clear, which would have been deducted from his bill if he had authorized any actual work, which was still badly needed.
I am absolutely certain his check engine light came back on within a day. I hope that day was worth 50 bucks.”