Need more info. It can be many things depending on the vehicle...
u-joint
motor mount
bushing
cv joint
exhaust hanger
internal transmission problem
it could be your valves or your engine
Serious engine knock or valve train noise. Have this looked into by a pro.
Typically, a knocking noise when to use your brakes in the car is caused by your brakes wearing down. This means you need to get them checked out and repaired.
warped rotors , brake
many many things, Loose lug nuts which lets wheel make knocking noise. Engine will make a knocking noise if it is really low on oil. Some timing belts make a knocking, slapping noise just before they break.These are just a few examples . Have someone ride in car with you as you duplcate the noise and see if they can determine which part of the vehicle it is coming from.
Its hard to say... do u know where the noise is coming from?
look under your car, drop the oil and go out and drive it for about 5 minutes then listenin to the loud noise of the knocking cam
When it makes that noise it is either because your reving it to high or just because your engine is goin
you may have a rod knocking and you need to take it to a shop asap
Usually a "knocking" or "ticking" noise when under acceleration means cheap fuel grade. Next time go for the gas with more octane such as supreme.
A loud knocking noise in the motor of a car at high speeds is most likely the engine. There could be another issue with the transmission if the knocking only happens at high speeds.
something might be lose under the hood u might want to get that checked out there could be something wrong with ur car how good is its condition