Crank Shaft.
There are many things that can cause vibrations in a 2000 Toyota Avalon. One such cause could be a bent rim and another cause for the vibrations underneath the floorboard is the engine.
No.
Cause low pressure oil pump
what engine?
When the fuel in an engine cylinder ignites prematurely or unevenly to cause power fluctuations and a "knocking" sound. usually occurs when an engine is very how or improperly timed.
Engine knocking can be caused by numerous things. Having the incorrect spark plugs, carbon deposits on the cylinder walls, and being low on engine oil may all cause a knocking sound.
Having a bad rod bearing could cause a truck to make a loud knocking noise and shake when driving at high speeds. The engine having a coolant leak or an engine timing problem could also cause the knocking noise.
it could be the center support bearing in your driveshaft
can you elaborate? engine noise? stationary/moving? ticking, tapping or a definite knocking?
Bad bearing or rod
Yes, fouled spark plugs can cause engine shaking, and loss or power. I'm not sure about knocking but I'd guess that too.
A bad harmonic balancer can cause a knocking noise. The harmonic balancer doesn't actually produce the noise, but it can cause the noise in the engine.