pump knocking

[Tresguey]

we can hear a knocking sound on my buddies boat when we took it out the other day. we didn't calk around the pump to the frame. could the bowl be hitting the frame making this noise?

[Moneypitt]

It is common for an unloaded pump to rattle a little, but to knock?? Are you sure its not coming from the motor???????...........MP

[Red Horse]

Check to see if the impeller is loose on the shaft. That will do it at idle, much more so if you have a performance cam in the engine.

[lucky]

u joints -- i bet , or rear bowl bering

[roostwear]

A knocking at idle can also be from loose splines between the coupler and pump shaft.

[wsuwrhr]

A bad front bearing can have the same noise.
Brian

[Duane HTP]

Does the knocking noise go away as you accelerate?

[Tresguey]

no it doesn't it gets louder and doesn't sound like it is coming from the motor. and we just found milkshake in the bowl.

[Captain no fun]

Sounds like the input bearing let go. That will relax the relationship between the impeller and wear ring. The other guys diagnostics are right on track, but once I had the bearing go away, and it created the milkshake. I thinkthat's where I'd start. Grab the shaft and try to lift it vertically, if it moves at all, the bearing is gone. :mad:

[Tresguey]

found the problem. i was listening as he rev'd the motor a bit and to me the sound was coming from the top end. so we pulled the valve covers to find a rocker loose and a push rod missing. pulled the intake and found the push rod laying across the lifters. good news is that he hasa new intake we were gonna put on and there is no damage. now maybe he will listen to me next time when i say to check the top end after breaking in a new cam. i'm still workin on getting him to drop a good ol Chevy in it. :hammerhea