share your expensive mistakes stories- Automotive only.
 

I once bought sight-unseen a 95 e320 wagon from a doctor who claimed it was in perfect shape. I turned out to have a blown head gasket and a collapsed driver's seat. I paid $3200 for it. I could not in good conscience resell the car to another sucker so I chose to donate it to charity (NPR).
Well, I got shafted again. The 'auction' winner was the local junkyard. He paid $300 for it. I could have sold it for scrap, got more $, and donated it all to NPR.

Lesson learned. NEVER buy anything sight unseen. To a lesser degree, don't buy a gasoline MB if you are used to driving a diesel. The change in mpg will take some getting used to.

too many...

"good shape 300SD" turned out to be a total wreck... and I drove to delaware to get it...

Replaced the water pump on a 1983 ford 6.9 liter diesel.
Used the same bolts from the old pump and the new pump was thinner.
The bolts went through and hit the fuel injection pump gear and when I cranked it up it sheared the
Shaft in the injection pump.

I didn't adjust my transmission modulator and tried to let off the pedal to ease the shifts. The frequent slipping killed it.

EDIT: I also tried to make it to the next exit in my 4.0OHV when it threw the serpentine. Stupid teenager move, it popped the headgaskets and radiator as I coasted into the parking lot. That one was painful.

Well....the 300CD comes close....very misrepresented by ebay seller, 6k invested so I can sell for 4, but at least someone will get a good car with all remaining defects properly disclosed.

Worst though was a '59 fairlane that I bought on fleabay. 'good running and driving car, no rust'. Went all the way to south florida to pick it up. Once I got the seller to switch the battery leads to the correct posts it did crank, one wheel was completely locked by the frozen brake. Floorboards were non-existent, and frame was rusted through.

You'd think I'd learn about fleabay......

About 1.5 Years after rebuilding the Short Block on My Volvo Diesel I managed to knock a Screwdriver down into the Timing Belt resulting in Pistons and Valve making contact.

I had rebuilt a Dodge Slant 6 Engine and got about 2 years use out of it. I attempted to solder up a leaking Radiator seam where the Top Attached to the Core.
While on the Freeway 6 inches of the seam started leaking.
By the time I had it off of the Freeway I had a good Rod Knock going on.

Pulling and taking the Engine apart I found the Crank Shaft damaged as well a scored Cylinders.
I saved it to rebuild it at a later date but managed to lose the Main Bearing Caps. Was out of work and gathered up all of My scrape Metal including the Block and sold it.
Several Months later I found the Bearing Caps in a Box.

rebuilt an 84 dodge 318 small block, did a full on rebuild, mains, rods, pistons, oil pump etc...

forgot the gasket between the oil pump and the main cap... scrapped the truck a few months later...

I've had a few...I dropped a hard object into the cylinder of my 52 caddy without realizing it and poked a hole in the piston. It was a freshly built motor. Cost at least 2500 to do over.....

Bought a Ford van with the 6.9 diesel, turned out it had a cracked block....a long sad story later cost at least 6000.

Those are prolly the top two....;)

If you're buying and selling old cars you'll get a bad one now and again.

55-gallon, stainless steel fuel tank developed the <still> unsourced fluke of a rusting out interior, necessitating replacement of it and the fuel pump too. Total cost: $4,800.00 or so - ouch!

ON EDIT: NOT really a mistake, but a costly mechanical product failure - several of those over the years.....

If we go for stupidest.....I had just rebuilt a 390 in a Cyclone GT and dropped it back in. Dist was out so I could prime the oil pump. Put dist back in, crank crank crank, gas gas gas, no bang. D'oh, 180 out, didn't turn key off, just lifted the dist up.

Old timers....you know what happened next.

As I pulled the dist out, the shaft turned a little, points did their thing and the now free distributor arced to ground setting off a crankcase explosion. Lost eyebrows, hearing for a few hours, distributor in ceiling of garage of rented house.

Snapped the camshaft on my M102 by installing the tensioner incorrectly - still haven't totally fixed it yet!

So thats how that distributor got stuck into that beam :D

I bought my Yota with a "rebuilt" long block 3.0 V6 sitting in the bed. Receipt from a shop for the rebuilt motor, contacted the shop and asked if they'd honor the warranty before I bought it. They said yup, they do good work, doesn't matter who owns it the motor will do well.

Bought another thousand dollars worth of top of the line Napa Lifetime parts - timing set, water pump, plug wires, etc. While I'm putting on the oil pan, I'm going hmm, I really should yank those main caps, relube them, retorque them, verify the right bearings were installed, etc. The paint pen markings on the caps and the thought of a voided warranty said nope, don't do it.

Finally got her all buttoned up and started. Ran beautifully for about thirty seconds, then tap.................tap..........tap....taptaptaptaptaptaptap.

Called the shop. Out of the 1 year warranty. PISSED, but yeah that's on the receipt I had along with the date.

Autopsy of the motor after I pulled it revealed one of the nuts on the failed main cap was finger loose. Didn't even need a wrench, just unscrewed it by hand. Piston was hitting the head. Lots of rust and junk in the cooling passages, the freeze plugs had another set of freeze plugs under them where the new ones had just been pressed in on top.

Called the shop and told them what I thought of their rebuild, and started planning my diesel swap.

The first time I pulled the chain tensioner on my 617, I didn't realize you had to re-set the piston to its starting position (thanks, Haines).

After a few miles I smelled burning oil and rubber and there was smoke coming out of the oil filler. The excessive pressure and subsequent friction on the tensioner rail was so great that the rubber lining on the rail was melted/burned off clear down to the metal.

new rail--$70
unneeded oil change--$20
New chain--$130 (about time anyways)

Bought a 2002 Trooper with a freshly rebuilt transmission under warranty.

Transmission started slipping almost immediately.
Took it to the shop and paid $500 for parts that weren't replaced last time.

6 weeks, no truck and lots of excuses.
"Lost his lease" and moved all vehicles to a new shop in another town. Transmission in pieces. Had to drive randomly around the town to find the shop.

After almost 6 months I towed the Trooper off his lot and bought a transmission from a junkyard.

The con-man had had three shops in three towns in two years. The current business license was under a fraudulent name. By the time I took my truck back, the shop had cardboard covered windows, a disconnected phone, street numbers removed and court summons on the door.
Met three other people with the same story. He even gave different names to different people.