What is the worst mistake you made doing your own wrenching?

I loved that car. Had tokico shocks and struts, trd springs and sway bar. Took a day and a half to get up to 60 but you never had to slow down for turns. Aside from the water pump I never had any problems in 160,000 miles until I totalled it (and by totalled, I mean I drove it 130 miles home with a tweaked frame). Got 8500 from insurance with that many miles, which is more than I'm about to sell my subaru that I paid $9000 more for and has 45,000 less miles.

 

I've done this. Had to crush the old oil filter to get it off, but didn't notice that the seal didn't come off with it. Proceeded to put the new seal on top of the old seal. Started the truck with the hood up and oil went everywhere.

 

How long did it run without a drain plug and oil?

 

I had a shop install a performance clutch backwards in my truck a few years ago. That sucked, lasted maybe a week or two before it was toast. Then I paid Toyota to fix it with a stock clutch just to add insult to injury to myself. Never doing that again lol

 

I was about 25. Changed the gf’s oil in her Camry. She calls me the next day while she was driving on the freeway, “hey, I’m driving to work and the oil light is going on and off.” Me “are you on the freeway?”. “Yes” she said. “Pull over. Now. I’m not joking, pull over into the emergency lane immediately and shut off the engine. Call me back as soon as you’re pulled over.” “Ok” she says. Two min later she calls again saying “the light is still going off and on”. “Are you pulled over?” I asked. “Not yet.” She says casually. “PULL OVER RIGHT NOW AND SHUT IT OFF!” I said (yelled). Another two min later she calls again:”the light is staying on now and the car sounds weird” she says. “Holy fucking hell what is this chick’s problem” I think to myself, before asking her something similar out loud. Needless to say I told her to pull over and turn it off again before she calls me back in another two min telling me the car is breaking down.

Obviously, I forgot to put the filler cap back on. Definitely a stupid rookie move. But one that could have been cleaned up with simple green easily enough.

We towed it back I and changed out the oil again. Ran ok but quite a bit noisier.

This chick went on to get a PhD in nutrition or something.

Definitely my bad but holy fuck.

Second worst mistake was not attaching the ground cable from the head to firewall after doing the hg on a 22RE in my 85 4Runner. Got about 15k miles on it before the head went again. Pulled it off to find a bunch of aluminum had been eaten away due to electrolysis.

 

In 1980s I over torqued and cracked the carburetor housing on an Oldsmobile small block that was a one year wonder. Could not get a replacement. Had to scrap the car.

That was the last GM I’ve ever owned.

 

I don't know if it counts as a wrenching mistake but I thought I'd mount my camping axe to my roof rack using Quickfists since Quickfists are all the rage in the overland community. Well, I learned the hard way that they don't hold more than a few pounds very well without reinforcement. Was on a very windy freeway in the desert going 75 and my wife and I hear a loud thump above our heads, I look in the rearview and see my axe twirling in the air behind my truck. Thankfully no-one was behind us and we were in the slow lane so it landed off to the side.

The stupid plastic washers that come with the Quickfists had snapped in half causing it to dismount from the bolt and off went the axe and the Quickfists. I remounted them with metal washers and haven't had any issues since.

But I keep the axe mounted in the bed now

 

Swap those out for metal ones trust me lol. Those plastic ones will break, especially if they're roof mounted and exposed to a lot of wind. The wind kept pushing the axe away from the mounts which eventually broke the washers and pulled the quickfists off in short order

 

Another fun time working on my Camaro was when I was troubleshooting a ignition issue with my MSD 7AL 2 plus Gold box ignition box

A friend of mine was helping test for spark by grounding a spark plug wire with a screw driver to the frame to check for spark . He told me to crank the engine over which I did and within seconds he's yelling "Stop" . I stop and he's yelling that he cant move his arm

He was hit by extreme voltage of 570volts Primary and 47k volts secondary . The voltage is so hot the coil wire will produce a bright white spark that is extemely visible even in bright sunlight


Here's a pic of my ignition box .....

 

Had a buddy change the oil on his girlfriends corolla. Except he drained the tranny and poured in the oil. So she drove around with zero tranny fluid and twice as much oil. I was helping him on the third time and I saw the two plugs and asked him about it. He insisted I was wrong. I google what the oil pan looked like. I let him do what he wanted. He drove it down the street and car smoked like you put sea foam in it. We drained it. Spilled oil all over the ground cause it just kept coming. Corolla was fine though.

 

2 best thing I whitnessed in person:
1) College roommate was changing the plugs on his old GTI. The old VWs used the snap on larger terminal on top on the spark plugs. After removing one of the plugs and looking at the snap on part on top of the plug, he took it off and dropped it. It bounced once off the core support and went straight down the spark plug hole, nothing but net. Being aluminum it wasn’t magnetic. Spending an entire day with grabbing devices we were unable to retrieve it out of the cylinder. A simple plug change turned into a top end rebuild.
2) Same college roommate, same car. Doing an oil change in his parents small 1 car garage on a college break. Got interrupted part way through. Came back and put 4.3qts of oil in and checked the dip stick. Dry. Looked under the car and he realized he pulled the collection pan but never put the drain plug back. 4.3qts poured directly on the garage floor.

 

came out from work and had a flat tire.
put the spare on and headed home. made it about 10 miles and something felt really funny, as i started to pull off the highway my wheel passed me on the left and kept going into the median of the highway. i got it to the rosdside on three wheels! this was rush hour of course. had to get towed. the only thing i could think happened was the inner edge of the lug holes on the rim had rusted enough that when i torgued the nuts on it it crushed the metal and the lug nuts weren’t actually seated. all the nuts came off and no broken studs. still wonder about that one

 

Hahaha!! Done the oil seal thing. It was in my cobra. 7 quarts of oil, all down the driveway. Agreed on cleaning it up. That sucked

 

Took the carb out of an old inboard boat so I could clean it. When I put it back in I didn't tighten the fuel line all the way. I went to start it, idled for about 10 seconds and then the motor burst into a ball of flames with me in the boat in my driveway. I hopped out and put the fire out with a hose. Had my back to the engine when it went so I was fine although it burnt all my leg hair off except where my socks covered so I had weird hairy ankles the rest of the summer haha

 

Cross-threaded a spark plug on my old 92 GMC 2500 with a SB 350.

 

In my misspent youth I had a 1979 Chevy 1/2 ton with a 454. The fuel pump went out on it. Back then fuel pumps were powered by a camshaft lobe pushing on a push rod that pushed on a lever on the fuel pump. I removed the old fuel pump and installed the new one. What I did not know was the push rod had slid down. I bent the push rod up inside the engine when I bolted on the new fuel pump. You are supposed to push the push rod up and hold it in place with heavy grease then bolt on the fuel pump. It took me a long time to figure out what had happened.

Anyway, turned into a big mess. I had to rig up an electric fuel pump.

And...This all took place out in the street with a water filled curb when it was freezing cold and sleeting.

 

We had this happen at a Nissan dealership to my wife's Xterra. Luckily I saw one had already fallen off and checked they rest on the wheel, none of them were tight.

 

Did you grow up in the 80s? Cause this is very 80s. Although it could be 70s.

 

The only thing I can remember is changing oil on a Cherokee when I worked at a Jeep dealer. I did the oil change and took it on a road test for something.
On the road test I thought to myself that I don't remember putting any oil in it. Got back to the dealer, checked the oil and nope, empty. Filled it and it was fine.

I can't remember anything I've done on my own cars.

 

Not with this truck, but my first car Ford Focus. Changed the oil and never put the cap back on the fill hole. Drove about 45 min to see my GF at the time and when I got there I noticed lots of smoke and the stench.