Okay i have had my car for a good 6 months, and i have noticed that when in 1st gear (5 speed) or reverse it will have somewhat of a knock. Now my mom was in the car and she said that it is bad gas, i haven't put higher octane it so i was wondering if she is right or is there something horribly wrong with my engine?

 

as a general rule of thumb, consider everything a woman says to be wrong............:rockon:

 

My friends Beretta 5spd does something like that. If it only does it in 1st and reverse and has nothing to do with engine speed or engine load then my guess would be its something in the transmission.

If it was making a little knocking sound only under partial load and went away while idling or full throttle i'd suspect its pinging and putting in higher octane would help.

 

Retard your timing a degree or two. Should fix it without getting ROBBED for premium fuel

 

Yeah 350cutlass... it will only do it under a little bit of a load, thanks for the unput

 

TWG in Texas,

What engine/fuel system is this? (It always helps to know.)

It could be inadequate octane, could be carbon buildup, overheated combustion chambers, lean mixture, lots of possibilities.

If it's ae early-mid '70s Olds, the valve rotators tend to make a slight "rattle" sound anyway, but it is distinctly different than a detonation sound.

 

it's a 305 tbi if that helps with 116k on it and it 's a 90 rs

 

a knock, huh...? just one or several ?

MY only 2 bits is this,

crawl beneath the car, as its on stands and take the E brake off and take it out of gear

grab the driveshaft and rotate it back and forth, check for backlash

If it moves considerably you may have a problem. maybe bad U joints, gears going out. but i dont know too much about drivetrain.