i wouldn't say they would cause a knocking, But i do no if you use cheap roller weights they start to deteriorate very fast and make a flat spot on it, so now u have what is supposed to be a round roller with a flat spot that's getting worse by the mile. Best bet is to check the weights see if there worn, if they are then yes it could cause some noise, if not then no should not cause noise. I highly recommend getting Dr Slider slider weights. They are not round but have a flat spot and hex shape, They wear way slower and provide better overall performance and longevity. Measure your roller weights and find out how many grams they are then click on the related link below, and find out the weight and size of your rollers. I f your weights are 6 gram get 7 gram so whatever weight you have in roller weight get 1 gram higher in slider weights. Because of the design, it takes more weight to equal the same output as the roller weight (might be wrong) but these are definitely the best weights you can get on the market.
worn, lose rocker arms
Normally caused by worn steering or suspension components.
Worn Ball Joint
I would check the suspension bushings, if one of them is worn it would cause a knocking noise.
Knocking is usually associated with worn main and rod bearings.
it could be a number of things ranging from low oil, worn valve seats, worn or broken springs.
most likely drop link rods worn common fault on zafira apparently
Could be a worn CV joint
Yes, wrist pins can cause knocking problems in an engine. If the wrist pins are worn or damaged, they may allow excessive movement of the piston, leading to improper alignment and increased clearance between the piston and cylinder walls. This can create a knocking sound, often referred to as piston slap, especially at lower RPMs. Additionally, if the wrist pins are not properly lubricated, it can exacerbate wear and knocking issues.
It sounds like your CV (Constant Velocity) joints are worn and need to be replaced
Perhaps a worn CV joint (usually more of a clicking sound when turning), but there are many components in the front end of a motor vehicle that could cause a knocking (or similar) sound, including suspension components, brakes, steering components and bearings. Worn tie rods, by the way, do not normally cause a knocking sound, but result in very loose feeling steering and noticeable drift, especially at highway speeds. A knocking sound is more likely to be an engine problem, such as pre-ignition. If you are not accustomed to diagnosing these sounds, you will best best off to see a qualified mechanic, or a friend who is more familiar with the front-end components of a motor vehicle.
It depends on the type of "knocking noises" you're hearing. Usually knocking noises are caused either by spun or worn main bearings, or worn wrist pins. Either way, it means you need a new engine.