Dumbest Thing You've Seen a Mechanic Do - PeachParts Mercedes-Benz Forum

al76slc · #1 02-06-2007, 08:35 AM

Reading the Jiffy Lube thread, seems like many of you have witnessed real dumb things by mechanics, although not necessarily only with the oil change drive-throughs.

I'm not sure I could recognize a dumb thing when I see it. The only thing I can report is an oily rag left on the exhaust manifold by my Indie. Oh, and vise grips used to unscrew the plug for oil changes. I've done a lot worse myself.

Note - I'm not dumping on mechanics.

Some of my best friends....

catmandoo62 · #2 02-06-2007, 08:44 AM

i guy that worked for my dad"who everybody hated"he was changing the oil on a car and leaning over the frontend .just putting in the last quart,and i don't know why but we just happened to be looking at him.anyway as he stands there all the sudden whoooop his feet come flying out from under him and he cracks his chin on the radiator.idiot forgot to put the drainplug in and the oil puddle finally got to his bootsand then he had 5 quarts of oil to clean up.god we laughed are butts off,only thing he didn't think it was funny.

t walgamuth · #3 02-06-2007, 08:45 AM

when the enthusiastic but not apparetnly very experienced tech at my indie took the engine out of my 280e euro for some reason he unbolted the flywheel (without marking it) removed the adaptor plate on the back of the engine and then equally inexplicabley put the fw back on.

luckily my favorite machinist caught it on reassembly. (the engine was sitting there with the fw on and no adaptor plate).

it was a few days before they found the matching marks on the crank and fw.

tom w

Carleton Hughes · #4 02-06-2007, 08:55 AM

I once watched an old-time "mechanic"pour tap water into the carburetor of a running Chrysler 413 with bad rings,he proudly claimed it would decarbonize the cylinders.
Indeed,there was a large black circle of carbon around the tailpipe,but I kept thinking of cracked cylinder heads,warped valves and hydrolock.

Some other guys swore by this method as well.

Shawn D. · #5 02-06-2007, 09:27 AM

Quote:

Originally Posted by Carleton Hughes

I once watched an old-time "mechanic"pour tap water into the carburetor of a running Chrysler 413 with bad rings,he proudly claimed it would decarbonize the cylinders.
Indeed,there was a large black circle of carbon around the tailpipe,but I kept thinking of cracked cylinder heads,warped valves and hydrolock.

Some other guys swore by this method as well.

That does indeed work quite well to remove carbon on the piston tops and combustion chamber. Sure, if you ran a garden hose into the carb, you would hydrolock the engine. However, that's not how it's done.

Once the engine is warm and running at a fast idle, pour the water down the carb at a rate that gives you about a 1/8" thick stream. If the carb has more barrels than one, vary between the primary barrels so as to get all branches of the manifold. If the engine starts to struggle, back off on the flow.

Once you're done (maybe one quart per liter of engine size is good), go for a drive to make sure any moisture that got past the rings is boiled off, and it'd be a good idea to change the oil.

#6 02-06-2007, 09:47 AM

About ten years ago we had a sales rep. at the company that drove a VW Golf with a manual transmission. He took the car to a local quick oil change business and got really screwed. The person who changed the oil saw a cap and decided to remove it and add fluid. The cap happend to be for some sort of visual inspection access for the clutch. The empolyee at the shop poured an unknown amount of brake fluid into the hole.

The clutch which by the way was recently new was ruined. As I remember I believe that he had to take the shop to court for the damages. (OH, Look, theres a cap. What shall I pour in there?)

Carleton Hughes · #7 02-06-2007, 10:11 AM

Quote:

Originally Posted by Shawn D.

That does indeed work quite well to remove carbon on the piston tops and combustion chamber. Sure, if you ran a garden hose into the carb, you would hydrolock the engine. However, that's not how it's done.

Once the engine is warm and running at a fast idle, pour the water down the carb at a rate that gives you about a 1/8" thick stream. If the carb has more barrels than one, vary between the primary barrels so as to get all branches of the manifold. If the engine starts to struggle, back off on the flow.

Once you're done (maybe one quart per liter of engine size is good), go for a drive to make sure any moisture that got past the rings is boiled off, and it'd be a good idea to change the oil.

Well, just for the hell of it I did it on a Willys-Knight sedan I drove around,smoky,carbony sleeve-valve engine. Just a little at a time,thru a small hose into the Tillotson updraft at mid-throttle and I must say the car ran much better with less vibration and I could advance the spark with no pinging,so it does have some merit,but I know a guy who did it to his 4 bolt Chevy and cracked 2 exhaust valve seats.

Pete Geither · #8 02-06-2007, 10:37 AM

Took my bike, a ZX11 at the time, in for front brakes. When I left , the brakes didn't seem quite right but I took it home thinking they just needed broken in. When I got home I looked and the installer had put the brake pads in backwards, with the backings against the rotors.

G-Benz · #9 02-06-2007, 10:44 AM

Knew a guy at my apartment complex years ago that worked on a fleet of school buses. Not the most brilliant, as he had had a few small fires at his place from errant cooking disasters!

Anyway, had a buddy who worked at the same place. He told me of one story where said guy couldn't undo the nut that held one of the brake lines onto the hub. So he proceeds to HEAT the brake line with a blow torch!

Minutes later the effect of the boiling brake fluid creates a resounding BANG! and he blows the line at the other end!

Dubyagee · #10 02-06-2007, 11:05 AM

There is a shop in SC call Precision Tune and I had a Chrysler Newport 440ci I took there for a tune and oil change.

I watched as he backed it onto the chassis dyno and connected an oscilloscope. He got in the car, put it in gear and brought it to about 70mph while watching the oscilloscope.

Thats about the time the car noticed the lack of wheel chocks and exited the building, Hood open, wheels ablaze and dragging the oscilloscope. Somehow he managed to stop the car before reaching the street. He got out of my car and leaned over the trunk while I ran outside to check the car to find a few scratches on the left front fender and a few sparkplug wires yanked off.

The manager came out and asked if everyone was OK. I got a free "tune" and they paid to repaint the fender.

Dee8go · #11 02-06-2007, 11:06 AM

Quote:

Originally Posted by G-Benz

Knew a guy at my apartment complex years ago that worked on a fleet of school buses. Not the most brilliant, as he had had a few small fires at his place from errant cooking disasters!

Anyway, had a buddy who worked at the same place. He told me of one story where said guy couldn't undo the nut that held one of the brake lines onto the hub. So he proceeds to HEAT the brake line with a blow torch!

Minutes later the effect of the boiling brake fluid creates a resounding BANG! and he blows the line at the other end!

I hope he's no longer allowed to handle matches!

TheDon · #12 02-06-2007, 11:07 AM

Not balance my tire when the order called for a balancing..Its common sense. New tire = balance it... And this was at a goodyear shop... Plus they didnt listen to me when I asked for the lugs to be put on with a wrench not an impact gun.. I had to have them do it two times before they got the idea...

WVOtoGO · #13 02-06-2007, 01:18 PM

Quote:

Originally Posted by TheDon

Not balance my tire when the order called for a balancing..Its common sense. New tire = balance it... And this was at a goodyear shop... Plus they didnt listen to me when I asked for the lugs to be put on with a wrench not an impact gun.. I had to have them do it two times before they got the idea...

That’s a big peeve for us around here. These guys with the impact wrenches slamming on the lugs. Then going back with a torque wrench set at some way lower (but proper)level and “clicking” on all the nuts. “Yes sir - Factory spec. That’s what their tightened to.” My ass.

Had a kid at an oil change joint read the max load at max psi on the side of a set of tires, and then fill them to that. 85psi, I think it was. Thank God I caught that one before I hit the brakes on a wet street. I think it gave me about a 4 square inch contact patch per tire on a Dodge Ram 1500.