1999 5.7 gsi volvo penta. knock?

[patbarb]

I have a 1999 four winns vista, motor sounds great but when I run under a load above 2800 rpms it makes a knocking sound in the back. Any ideas

 

[CV16]

Is it a motor knock or in the out drive? You might have to have another person drive so you can isolate the problem. Get a mechanics stethoscope and see what you can find.

 

[patbarb]

I can not tell if it is engine knock or in the out drive. Had a mechanic ride with me and he could not pinpoint the problem.

 

[Scott Danforth]

Pull the drive and run the motor on a hose hooked to the raw water pump

 

[jimmbo]

Does it knock at that rpm in neutral, or just in gear under load? Perhaps if the mechanic had access to a dyno, it might make it easier to locate the noise. Quite possible the CV joint is binding

 

[patbarb]

It does not knock in neutral, just in gear under a load. Thanks