This is not a rod knock. It's too slow.

At idle, the frequency of this tapping is around 450 taps per minute, or half the frequency of the engine's RPM. Since the camshaft spins half as fast as the crankshaft, the tapping coincides with the camshaft's period of rotation, not the crankshaft's.

If this was something in the bottom end, the tapping would be twice as fast. This is something in the top end.

 

piston slap or wrist pin issues will cause about the same noise but usually only at half the speed of the motor because it is worse when under pressure from the cylinder firing on compression stroke. pryor to 89 model 22r# there was a TSB on piston slap and wrist pin issues. Soon it is a known problem for Toyota.

 

toyotaPmanager is right as well. A rod knock is also worse under pressure hense it's not always at engine RPM.

Now if a full blown rod bearing wilshire would be correct, but just a worn out enough to make noise rod bearing can only make noises at half engine rpm.

Easy way to figure it out is to pull a plug one by one and see if the noise goes away.

However the O.P. did come back to say it WAS a rod knock. How he actually diagnosed it, who knows.

 

well I ended up doing a rebuild on my motor and it turned out I had spun a bearing. I wanna say it was on cylinder 3. It was the one on the bottom of the rod and the crank shaft (very technical terms I know lol)

 

Crank bearing on number four cylinder is shot, warped block. It got to hot, mines done it and sounded just like that. Sorry man, but im 90% sure im right

 

dose it have oil preshere