Please tell me I'm not the only to make this mistake?

[dave73]

Over the winter I put my battery in the trunk. I re positioned it for mounting and didn't realize I flipped it 180. Hooked up the positive and negative to the wrong terminals and quickly saw the smoke show...

[340challconvert]

Was working as a mechanic in an Exxon station (early 70's) changing out umbrella valve seals that were leaking with the heads on the car on a large Mercury. Standard procedure; using a screw in air hose in the spark plug hole to keep the valve from falling into the cylinder while changing the rubber seals. Bumped the hose at the cylinder accidentally. Interfered with the air seal long enough for the valve to drop before I could install the spring and keepers.
Needless to say, ouch. Had to pull the heads and offered a full valve job on the customer's car. Luckily the car belonged to a doctor who took the mistake and larger bill in stride. Lesson learned till this day!

[RUNCHARGER]

I built a nice 440 for a 67 GTX I had. When I put the oil pump together I put the relief valve in backwards. I had lots of oil pressure, enough to stretch a Baldwin filter body and spit 6 quarts on the ground past the O-ring. I never had that problem again after that though.

[Spikedog08]

lol I would never do anything THAT stupid!     Funny though! 

[72 Challenger]

When I was younger I worked on the neighbourhood's cars while I dreamed of Mopars. It was a 1993 Nissan 240Z with an SR20 swap. Super common, I have done so many that is was like clockwork. The coilover wasn't working right for some reason I assumed it was because the bolt holding it down wasn't on it. No biggie. Shove that bod boy in with my hand and hold it down while my buddy goes and turns the ignition. F@ck me. What a shock. Turns out the housing was all buggered.

Working at a friends farm on their indestructible, stupid reliable, 50's era Massey Ferguson I put down a ratchet across both battery terminals. Welded on there solid.

Stupidest ever award was my alternator on my last challenger. It just was not going on. My patience had evaporated, I lost it and with two hands over my head I threw it down the driveway. Smashed into pieces. It was clearly at fault, stupid thing. Turns out it was the alternator to another car. GRRREAT. Now my policy is to walk away. Try again tomorrow.

[Spikedog08]

I do remember a buddy of mine dating a girl that was really good at making sure the car had enough oil and added oil whenever it was low . . . Problem was she was checking the oil while the car was running.  Ended up blowing up the engine and the mechanic stated that the whole motor was completely full of oil.   

[jimynick]

I bought a 340 out of a smashed 68 GTS and found it was tight as it'd sat in the wrecking yards back room for 3 years. I pulled the plugs and made up a witch's brew of trans fluid, diesel fuel conditioner and lacquer thinners and filled all the cylinders. Every day or two I'd try to get it to turn over, but no dice. Finally, having exhausted what little patience I had, I hooked a battery to it and jumped the starter. With a grunt the poor old starter tried, but failed to turn it over. By now, really pissed, I said FI and went and got another battery and set of jumpers and daisy chained them to give me 24 volts. I hooked the positive side right to the starter and with a fabulous display of arcing sparks, clamped the negative onto the block. Well! The tortured starter gave out a squeal/groan and suddenly it spun over!! Too late, I was standing beside it as the whole left bank puked-shot the contents of it's cylinders right in my face! LOL Try to picture a fool, all covered in oil/thinners trying to wipe it out of his eyes while trying to disconnect the howling starter and you'll get the picture.  The only upside to this was that that engine ran for years in my cars and I still have it to this day. Lesson learned- the hard way. 

[js27]

Back in the 70's I was putting my 440 together for my 67 GTX and I was just about finished and just torqued all the intake bolts down. I turned around to get the rocker arms and pushrods when I see 16 shiny lifters sitting on the shelf---DAMN I hate when that happens.
JS27

[RzeroB]

This really isn't a "mistake" ... but it does involve a bit of uneducated stupidity so I thought that it might fit in here ...

Was at this bar, hit it off with this girl and we decided to leave and go to her place for some fun. We hopped in her battered Volare, she fires it up, and the engine starts making all sorts of racket. I look over and notice that the oil idiot light is still on. I tell her "see that light and hear that noise - your engine has no oil pressure - you're going to ruin it if you don't turn it off ..." She looks at me with that "I know what I'm doing" look and says "no, you're wrong - that's my oil is low light and I need to just add a quart of oil. Do you want to go back to my place or or talk about the oil light?" Hmmm? Only took a second for the little-head to take over and I said "I was wrong, you're right - drive on!" Somehow we made it to her place, but the tortured sounds coming from that motor almost killed it for me - I couldn't wait for her to turn that poor thing off.

[71GranCoupe]

This really isn't a "mistake" ... but it does involve a bit of uneducated stupidity so I thought that it might fit in here ...

Was at this bar, hit it off with this girl and we decided to leave and go to her place for some fun. We hopped in her battered Volare, she fires it up, and the engine starts making all sorts of racket. I look over and notice that the oil idiot light is still on. I tell her "see that light and hear that noise - your engine has no oil pressure - you're going to ruin it if you don't turn it off ..." She looks at me with that "I know what I'm doing" look and says "no, you're wrong - that's my oil is low light and I need to just add a quart of oil. Do you want to go back to my place or or talk about the oil light?" Hmmm? Only took a second for the little-head to take over and I said "I was wrong, you're right - drive on!" Somehow we made it to her place, but the tortured sounds coming from that motor almost killed it for me - I couldn't wait for her to turn that poor thing off.

Did the "Low on Oil Light" conversation ever come up later?   

[HP_Cuda]

Here's one for ya.

I was working on let's say another car that I owned since I was 18. I was 25 at the time and this classic needed a new fuel tank because I got sick of changing out the fuel filter with regularity. The tank wasn't that expensive and my grandfather was in town that week (he taught me a large part of everything I know) and so I thought I'd show off to him a bit.

Well I'm under the car and I thought I'd gotten all the fuel out of the tank. So after unbolting the tank I decide to pull the lines directly from the sender and guess what. Splash right in my face and eyes, oh the burn but that all paled in comparison to doing it in front of my grandfather. On the upside, he had a good chuckle while I ran inside and ran water over my face.

[RUNCHARGER]

My friend Wade bought a new shortblock 340 for his 70 Swinger 340, mounted the new clutch to it and installed it in the car. Couldn't get the clutch to release. Pulled it out and the car never ran again (this was 35 years ago). Took the car to the local college to get the body repainted and the body was stolen, never to be seen again. I pulled the bellhousing off the 340 for him and you guessed it, he installed the disc backwards.

[JonH]

Lot's of good stuff here.

Back when I used to drag race, we went to divisional points race out of state. Picked up our trans on the way and installed it at the track. 2 or 3 of us put it in the car. Not a big deal as it was a tube chassis, with removable tunnel. Once it was together, we went and made a pass. Couldn't figure out why the car had slowed down. In the middle of the night I wake up and it dawns on me that we may not have bolted the torque convertor to the flex plate. Next morning I ask if anyone had put the bolts in. Nothing but crickets. We get to the track, and sure enough, no bolts. Long story short, by the time we had warmed the car and checked everything else, the convertor snout had welded itself to the crank. It was tight enough that the car actually performed, but was slow by several 10ths. Needless to say we were on our way home early that day. Major brain fart or too many cooks in the kitchen.

[73440]

When a routine is changed or a time crunch or interruptions occur , recipe for trouble.
And I have learned not to adjust rockers after drinking a half bottle of whiskey.

[Gary]

Here's a funny story that happened to us.  We have restored a number of straight axel  Corvettes for Bill.  Bill enjoys doing some of the mechanical work himself.  We were restoring a 61 if I  remember right and he had rebuilt the engine and rearend. We put the car together, and as is usually the case, the maiden voyage was to the alignment shop. We drove the car on the trailer, hauled it to the shop, and drove it in on the rack. Later that day they called to say it was done, so we went to pick it up.  My brother was backing it out of their shop when it stopped moving. I looked underneath and the driveshaft was spinning but the rear tires weren't.  Oh great.  They helped us push it on the trailer and seemed to get a kick out of our predicament.  Now we live near a small town and word gets around. I don't know how many times I was asked, What happened to the Corvette? So here's the story.  We got home and I called Bill and told him what was going on. He said check it out and I can take the third member back to the guy that rebuilt it if that's the problem. I pulled the axles and noticed that one was shorter than the other, I called Bill and told him somebody cut one of your axles.  He told me that he had bought a posi third member and had taken it to his "mechanic" to get rebuilt. Bill was putting the rear end back together and couldn't get one axel in all the way. He was told by his "mechanic" that posi"s have one axel shorter than the other. Just cut it to fit. I said that's your problem, it's not going in far enough to engage the post unit. He found another axel, we put it together, delivered it, and everyone was happy.  A couple months later I got a call from Bill. He said his "mechanic" had called and asked if he had ever found out what the problem was with his Corvette. Bill told the story and said you shouldn't have told me to cut the axel.  Bill said there was a pause on the other end of the line.  And then the guy said Ahhh Bill, you don't have another Vete axle laying around, do you.  True story.