Banging

[Jrato14]

Hi all,
So lots going on here. I have twin Volvo gxi which has ran twice since extensive yard period to replace y pipe and steering seal among other smaller issues. I was out today and everything looked fine but while coming up on plane the starboard engine reduced in rpm’s and I can hear a loud banging above 2300 rpm’s occasionally. The oils pressure is also lower than the port. The port also will not run up past about 2500 along with the port doing the same. Once at the dock I tried to run them up with drive disengaged and both sounded fine and ran as usual above 3500. During this entire run temp was fine

 

[Scott Danforth]

What was the last time the drive was pulled for annual PM?

 

[Jrato14]

Twice this year

 

[Jrato14]

Once for the bellows and such and the other for the steering seal

 

[alldodge]

Twice this year

With the banging starting and stopping, first make sure your drive is not trimmed up to high

If trim is within limits and still get the banging, then I would suspect the folks working on your drive are not doing much. It's most likely the U-joints

 

[Jrato14]

With the banging starting and stopping, first make sure your drive is not trimmed up to high

If trim is within limits and still get the banging, then I would suspect the folks working on your drive are not doing much. It's most likely the U-joints

Believe me u joints would make me thrilled compared to other catastrophic outcomes. What do u think of low oil pressure and bothe engines not coming up to speed

 

[alldodge]

The port also will not run up past about 2500 along with the port doing the same.

Note in above statement both say port, so this is only happening with port?

Also noting if the rpm does not come up under load on starboard (STB) this would be understandable, because the STB motor can not spin up same RPM under load with port being low

 

[Jrato14]

So it’s only happening with port but starboard won’t get up to speed either but what u said makes sense