Hi Scotty I have a 2011 Buick LaCrosse four cylinder automatic and it was making a loud noise so I took it to a mechanic and now they're telling me that there's a knock in my motor and that I need it replaced and I had a friend hook up one of those things under the dash that tells you what's wrong with the car and it didn't say anything about the motor it said I needed new spark plugs and there was a leak in my exhaust pulse a couple other things I really wish you lived closer to me so I could bring my car to you please help me what should I do
Spark plugs and an exhaust leak will not cause loud, knocking noises. If you have a bad rod, THAT will cause a loud noise and indeed the motor is in need of rebuilding/replacement.
An OBD-II scan tool does not check for rod knock, piston slap, etc. It would not tell you that your motor needs replacement. Only a mechanic is going to be able to tell you that, and only once they have physically inspected it.
