For all you yukksters out there, skip answers like, “Buying a Ford/Chevrolet/Dodge” that’s not the intention of this question. No, we want to know a screw up you have made while wrenching, racing, or just living as a gearhead. It happens to all of us and it always seems to happen during times when we least expect or need it to happen. We’ve all had situations where we accidentally drop something down the throat of a carb and fire an engine only to hear horrible noise and failure soon after. There’s got to be a few of those.
I’ll lead off the proceedings here. My dad and I had built a fresh engine for the Nova we raced together when I was in college. Motor in, starts up, runs good, life is perfect. We take it to the drag strip, I proceed to do my burnout, stage the car, mash the gas and there I go, rocketing down the track like a hero with our new, much more spiffy engine. Meanwhile under the hood. Things are not happy.
We had neglected to put the bolt into the small hole in the front of the block that is drilled all the way into the cavity where the fuel pump pushrod lives. At idle and low RPM operation this is no big thing. BUT, when you are roaring down the track with the engine spinning 6,000+ and its on the floor, this becomes a larger issue.
We hosed oil down almost all of the track and I was damned lucky that I did not get into said oil and wreck the car. That was pretty embarrassing.
Then there was that one time my buddy Dave at the gas station sent a customer home with no FEAD on the engine of their car…
BangShift Question Of The Day: What’s The Most Embarrassing Mechanical Mistake You’ve Made?
Just 1?? Over filled the trans on my first race car and vented so much oil that it started a header fire at 100 mph and stopped racing for a half hour. ( I worked in a transmission shop) Sheared a pinion on a harried 2-3 shift in customers 428 Pontiac after a clutch install. Sent a 4 speed Mustang II down the road without putting lube in the trans. Installed valley pan under intake in backward and couldn’t get distributor in. There are more, these are just a few of the things I did before I was 20 years old.
1st engine rebuild when I was a teenager, I noticed the oil ring expander was a bigger diameter than the bore so I thought you were supposed to file fit like the other rings. Started it up and there was so much smoke I had to leave the garage. Oil was RUNNING out of the open headers! Called the ring company and gave them the story. As we all know (now), he said that the expander was supposed to be bigger to put tension on the scrapers. He sent me new expanders and I had to tear the engine right back down.
Dropped a screw into a distributor when replacing the points, forgot about it, and cranked the engine. Broke the distributor gear.
Didnt put the oil galley plug in next to the distributor on a big block chevy and fired it up which sent an impressive stream of oil straight up into the rafters of the garage which spattered pretty much all over everything. That was a quality mess!
Let a customer’s carbon fatbike slip out of my fingers and right into the repair stand cracking the toptube. Custy was very cool about it, getting a new frame courtesy of my boss and all.
This one still gets me every now and again. Forget to check for the gasket on an oil filter when removing it for an oil change. Put the new filter on with the old gasket stuck to the block. Start it up and there is oil every where.
did an oil change in a big rush someone distracted me asking questions and i dropped the truck down filled it will oil and drove it to the lane with the customer watching oil pour out of the oil filter location – minus the oil filter… biggest mess i ever made
Forgot the oil plug resulting in 4 quarts on the ground worse part is I started the car with no oil. sounded like a diesel. 4 more quarts and drove the hell out of it.
Swapped a tired 273 for a stout little 360, in an old Dodge Dart. Moved the intake, timing chain cover, etc over to the 360. With a splash of fuel in the carb, it\’d fire up and run for a couple of seconds. Wasn\’t getting fuel. Looked over at the 273 on the engine stand….fuel pump eccentric didn\’t get moved.
plumbing the fuel pump backwards on my first 302 build and wondering why even the new pump i bought was bad.
Going for a drive in the same car and remembering that the hood didn’t have a latch anymore and i didn’t put in the pins about the time the hood came up and hit the roof
Ive got 3 good ones, 1 that I did, 1 from a manufacturer and 1 I watched a co worker do.
First off my oops moment. I had drained the trans on a small John Deere tractor. I started to fill it back up and ran out of oil. I went to get more and when I came back my boss was standing there. He asked why I had more oil when there was 4 gallon jugs behind the tractor. I said because its not full yet. He told me it only holds 3 gals and pointed to my now overflowing drain pan. I guess I should have put the plug back in, would have saved a lot on oil dry.
Second was a co worker. I worked at a truck dealer, customer came in with a heavy haul Peterbilt. C15 cat and a deep pan. 115lb co worker could not break the drain plug free so someone else suggested he hit it quick with the impact to loosen it. Problem is he had poor trigger control. The drain pan was next to him and he was under the engine. He put the socket on the plug and held the trigger until the plug spun out and 15gal of oil started running out all over him.
Third is one of my favorites. Customer buys a new riding mower, name brand v twin engine. Mows his yard for the first time and as he gets on a hill it starts smoking like crazy. He immediately brings it back. I take it out and mow the ditch in front of the shop, no smoke so I turn around and head back in. This time the other cylinder is down hill and it starts smoking so bad I cant see where Im going. Pull the engine off and tear it down. NO RINGS on one piston, .1hrs on the hour meter, this was a brand new engine, OOPS!
Found out that you can actually swap the front upper and lower control arms (from side to side) on a 1970 Cutlass while rebuilding the front end.
Put the clutch disc in backwards on my 1973 Dodge Tradesman van. No biggie, didn’t have much to do that day anyway. Forgot to tighten the rear brake shoes centering bolt on my 1978 HD XLCH. Didn’t forget to spin the wheel and hit the brake pedal, just didn’t tighten the bolt. Distracted, too many people on 1 joint. Never woulda happened if I’d been smoking alone.That’s ok,1st year dual front discs stopped me before the end of the alley. Only took 2 weeks for my elbow to heal up.
Forgot the converter bolts during a pit thrash at a national event between rounds 4 and 5. Couldn’t figure out why I couldn’t get the Glide to move when I put it in gear to check the fluid level. Time ran out just as I saw the three nuts/bolts/washers under the dragster. Had about ten people trying to help me figure it out.
Put 8 quarts of oil in my N2O 572 (oil pan has no dipstick). Forgot about that first 8 quarts and a week later dumped in 8 more quarts. First N2O pass of the season melted about 6 pistons due to all the oil going past the rings. Stupid costly mistake.
Put a 360 together in a modestly lit garage while stretching my eyeglass prescription. Put the timing set together with my glasses out near the very end of my nose, and occasionally looked over the top of them. That can make the rectangular timing mark look a lot like the oval timing mark. The car made NO power above 3500 rpm, and had a 3800 rpm converter. It launched awesome, and fell on its face just past the sixty.
The repair fiasco led to water in the oil pan, which led to cam bearings in the lifter valley. This situation is not compatible to getting the car down the track consistently.
I also found out the hard way that mini-spools are not compatible with a great starting line, fresh slicks, and a trans brake. Even behind a torque-challenged 360. I was, however, able to salvage everything in the 9″ except the gear set, the carrier, the carrier bearings, the center section, and the axles.
2 am , my bike 750 katana , cant figure out why forks wont fit triple clamps , top alloy clamp goes in the press , $400 nz later mistake fixed .
Installing the distributor in an Olds 455 and getting it wrong. It made a little oil pressure, but soon enough dropped while powering my boat in the middle of the Willamette river. Ate the entire bottom end, didn’t have the money to get it back together, eventually sold it as a project.
Removing a cylinder head on a ’75 Celica. This was my first time doing a valve job but made a slight error of forgetting to drain the coolant! What a mess that was to clean up.
Head gasket repair (age 17) on my firebird. Haynes manual said to set zero lash and ad 1 turn which lifted the valves off the seats. Car wouldn’t start obviously. Tore that SOB down a number of times before realizing their definition of one turn didn’t match mine. I hate those manuals to this day.
A months long thrash to finish a restoration, we were days away from the customer loading up for a 1000 mile trip to the Mopar Nats in Ohio. I bolted the right valve cover on, and failed to notice the bolts slightly bottoming out before squishing the gasket. What a mess that made on the first test drive! Spent the next day and a half cleaning oil off of every crack and crevice of the newly finished nut and bolt restoration underneath that poor car. May have created almost as bad of a mess a SECOND time, after changing gaskets and covers, and not bolts, suspecting Chinese junk to be the culprit.
Had a 340 6pak challenger t/a stocker.Decided to install mechanical linkage on the carb setup for better off the line throttle response. Got it loaded on the trailer and went to the track. Cranked it up to get it off the trailer and the linkage stuck wide open. Motor went to 8200 rpm instantly. End result was one wasted two and a half hour drive to the track,plus entry fees,gas,etc. Not to mention sixteen bent custom pushrods (brand new),same number of bent valves,ruined keepers,etc. Threw that linkage away…
Pair of’em ……
Wife’s early Bug. Rebuilt the mill because it wouldn’t fire at all. Had to pull & pop it by hand, no cherry picker. Finally discovered the unhooked gas gauge cable three days later.
Hey, I was only 24.
Early 235 build & swap into my ’54 rag in auto shop at school. Teacher let me drain the battery, then try to push start it for two days, before schooling me on that distributor caps’s 180 degree pair of locating lugs …… in front of the class. One & only time I made that mistake. 😀
Hey, I was only 16.
Put the flexplate in backwards on a 85 k 10 and didn\’t discover it until all I liked was the torque converter bolts and flywheel cover. ASE master tech for 24 years. Kicked on a 1954 panhead Harley for an hour to find out it was out of gas, which was the first thing I ask the owner when I got there.
First time I did a valve job on a mid 60’s Buick found out the head gaskets had one coolant hole that had to be lined up. Everything else fit. Put coolant in only to see it running onto the shop floor between the heads and block.
Much later in my career when automobiles first had computer controls, many people had their car towed in for not starting blaming the computer. Crawled under each car as they came in, tapped on the gas tanks only to find them empty. A lot of wrecker drivers got rich for awhile.
One lesson I learned early on was that dots on timing gears were a lot different than key ways. Became very familiar with Pontiac engines after that.
I was still in High School, started working for a big box store oil change facility that we’ll leave un-named….On the way to school one morning, after a weekend of oil changes, I noticed a truck that had come through for an oil change recently was being hauled out of town on a flatbed/rollback truck. I remember the oil pressure gauge acting funny on the truck after the oil change and just chocked it up as a faulty gauge…….nope, it popped the motor and the company I worked for had to purchase a new motor for the customer. Felt super bad about it but hey, the dude getting the oil change done knew the motor was going and brought it in knowing some young punk wouldn’t even notice the gauge initially pulling it into the shop bay and got a freshly baked motor out of the deal. Lesson learned.
Had a pinhole leak in a funny car style pan on an injected alcohol engine. Drained the oil, left the plug out for a day or so to let it air out. Too lazy to actually take the pan off the engine. Lit up a stick welder, touched it to the pin hole and BOOM! the remaining oil fumes in the crankcase lite up. It was a 440 Chrysler and it blew the valley pan to pieces, took out 5 or 6 injector nozzles, 5 or 6 injector fuel lines, ballooned the oil pan.
Never weld nothing that isn\’t off the car and properly cleaned.
Had a pinhole leak in a funny car style pan on an injected alcohol engine. Drained the oil, left the plug out for a day or so to let it air out. Too lazy to actually take the pan off the engine. Lit up a stick welder, touched it to the pin hole and BOOM! the remaining oil fumes in the crankcase lite up. It was a 440 Chrysler and it blew the valley pan to pieces, took out 5 or 6 injector nozzles, 5 or 6 injector fuel lines, ballooned the oil pan.
Never weld nothing that isn’t off the car and properly cleaned.