Change you top strut nut.
Many causes and different for front wheel drive and rear wheel drive cars. It's hard to say without more detailed information.
Knocking is usually associated with worn main and rod bearings.
Driving at 50mph or above what causes a loud knocking clicking sound during acceleration?
I had the same problem when I cleaned and replaced my KN filter after 3 months of use. It was caused by too much oil on the filter element. It fowls the knocking sensor on the engine and causes the knocking noise at idle. I removed the filter and cleaned it. Then I very lightly oiled it and replaced it. The knocking went away in about a week. If it doesn't, you might have to replace the sensor. I'm not a mechanic... this is all the help I can give you. Good luck!
a dog
Mine did the same, mine was a motor mount.
You forgot to let your wife in
cv joints
A little kid in the trunk with a hammer
it could be your valves or your engine
If the brakes are too loose that could be a result.
counterbalancer is bad