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

Ive only broke a couple bolts. Nothing huge… yet.

 

Had an '88 Mustang and it would run fine, and then it wouldn't. Sputter and spit, and then act like nothing was wrong. Maybe it was the fuel filter? Changed that...same symptoms. Air filter was pretty damn dirty, MAF sensor, kept on with the "shotgun" troubleshooting for a while. Kept throwing parts at it. Finally, used a tax return and took it in before I was going to sell it. The mechanic puts it on the diagnostic machine, and says basically the ECU is fried and its a wonder it has lasted this long. Changed that out, and it purred for another couple years, sold it to a friend and he drove it forever.

Second story...watched my stepson and his "smart" car friends change out the brakes on his Civic. When they pulled the old pads, one of them grabs brake fluid because the reservoir was low. I didn't say anything, walked over to the far garage, grabbed a bag of cat litter and put it by the gang. Then they squeeze the piston to get the new pads in....out comes basically all the fluid they just put in...all over the firewall and the garage floor. I just laughed to myself and pointed at the cat litter and the broom. He didn't want my help, but that didn't stop me from watching the free entertainment.

 

And the same size. Fuquers.

 

We're guessing not very long. Someone at the check point saw the oil flow out and there was no oil trail behind the bike so I assume the plug had just fallen out.

 

Tried to remove a sway bar end link, but it the bolt was seized on one end. Put the wheel back on to took it to the shop with the one end out, and it gutted the CV axle boot. Grease everywhere. Had to get a new CV axle. Lesson learned. Cut end links off with a grinder or put the other end back in before driving. Never let it hang. Even for less than a mile.

 

Wrench slipped on a vehicle and knocked off the $90 plastic oil pressure sensor.

 

Started working on my 40. Put a 383 big block in it. Rear main leaked. Replaced rear main, leaked. Replaced again, oil pressure pegged and blew out seals. Had engine rebuilt (432 stroker), and decided original frame wasnt worth keeping. Built new 4 linked frame. Decided I didnt like how rails attached to back half and built 14 point cage. Its a never ending cycle.

 

not on the truck but machine at work has table saw style blades on it. four bolts on each blade. we use copper antin sieze and just snug them. one was tight and cheater pipe on allen wrench i broke wrench off in bolt head. got shop to come out and they spot welded a socket to the bolt head.came rite out!

 

I put a check valve in wrong on a Holly 780 double pumper on my '68 Cougar with a 351 Cleveland and it caught fire burning the whole car.

 

Jeeps just prefer to always be leaking. There's a reason they come from the factory already leaking.

 

Oh yeah I had the a leaking rear axle repaired 2x on my 2000 Grand Cherokee. Traded it in for my 4runner and never looked back. Never even made it to 90000 miles.

 

Was that Mustang a California car? If memory serves me the 1988 only had Mass Air in CA and then nationwide in 1989.

 

Busted my axle just trying to replace a torn cv boot on my 18 golf R. Thing wouldn’t go on the spline after I took it out and had it towed to the dealership and they tried charging me over 1,200$ and suggested I get my insurance involved. One call to corporate VW North America fixed that and they had my car ready the next day with a new axle and wheel bearing at no charge covered under warranty

 

Graduated high school in 1984. After reading your post... seems like you grew up around the same time?

 

I helped put an engine back in a 59 Willy's CJ5 and my cousin put the clutch in backwards. Didn't break anything, but when he hopped in and hit the clutch it just pushed to the floor. His dad instantly realized what happened. Luckily that jeep was easy to work on. Had the engine back out, clutch fixed, and back together in 20 - 30 minutes.

 

Letting my 14 year old son reconnect the two hoses from my remote oil filter on my old 1981 Chevy C1500 truck. Even after showing him which hose went to which connection on the oil filter replacement fitting he connected them BACKWARDS. Oil pressure gauge WILL show oil pressure when connected this way, just no oil flow, or little, if any. I didn't check his work. MY fault, I take responsibility. I can tell you that I must have put that 350 together pretty damn good, because it made it 92 miles before it even started knocking, and, knowing that I was looking at a total rebuild or a crate longblock if I was going to do it right, I drove it 67 miles back towards the house before it threw a rod out the side of the block. All while carrying a cab-over camper and towing a Ranger bass boat. Yep, pretty damn good work if I do say so myself. So if anyone ever asks you how far a 5.7L Gen 1 GM motor will go without oil while carrying a hell of a load and pulling another hell of a load, you can tell them 159 miles.

Replaced it with 400 block with a forged steel 350 crank blueprinted and balanced, turbo 400 behind it. Best favor my son ever did for me. Best tow vehicle I ever had!

He's now a Mercedes Benz mechanic...

 

You know, if you wire lights backwards they eat light like a black hole...

 

I've had some funny ones for sure. Usually its a bad purchase that leads to me doing more wrenching than usual. Rebuilding my 300zx I've had moments where the FSM has been wrong, I know you're all thinking "It's you that must be wrong dumbass" and I thought so too. But the manual was actually incorrect and because Chilton's stole from the first edition of the FSM for their book it was never corrected haha. Oh well, it led to me removing and installing the transmission four times. Now I can do a trans swap in like an hour and a half though so I got that going for me.

 

Did the same, but actually did drain the tranny fluid. Seemed to be in the same location as my Wrangler... When I realized the oil was the wrong color it was too late, but no harm to the truck. A little bit more expensive oil change and learned how to do a transmission fluid flush. Should be good for awhile longer now.

Sorry just saw this was for 3rd Gen.

 

Doing a timing belt on a Nissan Frontier, while replacing the cam seals one of them went on too easily. I though about it for a little while but ended up leaving it in.

Finished the timing belt job. Started the engine and sure enough, starts leaking from the cam seal

Had to redo the whole job since the cam pulley had to be removed in order to change the seal again