Back in my younger days, a buddy of mine had a 75 Buick convertible. I thought I would help him by adjusting his carb. It never ran right after that. We brought it to a old time mechanic, who was very good. He removed the air cleaner, fiddling with the carb he said ''who fuked with this carb'' my buddy said ''my friend did''(i was standing right there btw), the mechanic replied "well whovever it was, needs his fukin fingers chopped off so he never does this to another carb again". Needless to say, I went back and did some homework on the proper way to tune a carb lol. It wasnt a stupid comment on his part, but funny none the less.

Other than that, one of my favorites is ''Synthetic oil will cause the roller wheel to skid on the cam, and ruin the lifter, its too slick, so only run conventional. "

Having worked as a mechanic at both an independent import shop, and at a Pontiac/GMC dealer, I couldnt tell you all the stupid comments I've heard over the years from mechanics.

My wife had a POS '88 Olds Calais she bought new with the now infamous Quad 4 motor. At 7K miles the motor, while idling at a stoplight, locked up. The mechanic at the dealership told me Olds probably wouldn't warranty the motor. I asked him why he thought that would be the case. He said, "Well, the oil has never been changed in this motor. We have no record of ever servicing this car and there is no oil change sticker in the door jamb." I told him I change my own oil. Again, he repeated he could not find an oil change sticker anywhere on the car. I laughed at him and told him I didn't need to put a sticker on the car because I can count. I then looked at him and said, "3, 6, 9, 12, 15, 18...I can do this all day long!"

Yeah, their is a switch under the dash so you can set it depending on which country you are driving in. Idiot.

they all make that noise once they wear in. This was a grinding in my transfer case on a dodge

"I'll have it ready for you by the weekend".

or

"It's fixed, you should be good to go".

Yeah, that engine was a poor design and breaks quite often for various reasons. But, think about the fuel you're saving.

Many years back ,someone put together a list of entries from aircraft log books. Lots of good stuff but I can only remember a few:

After multiple attempts to repair an eng mis-fire. Mech stated "eng cannot be fixed".

After a pre-flight inspection, pilot enters in logbook "evidence of hyd leak in right wheel well".. Mech replies "evidence removed".

On another pre-flight insp, pilot enters in logbook, "oil seepage on propeller for #3 eng". Mech responds "oil leakage normal". Pilot makes another entry, "propellers 1,2 and 4 lack normal oil seepage"

Pilot enters in logbook, "#3 main brake wear pin almost at wear limit". Mech responds, "almost replaced #3 brake assy".

It is what it is

"Your car now has 30,000 miles on it so you need to have the 30,000 mile maintenance. It will cost $500." For nothing..

"Your boat is steaming because it is humid out" This was a good one..