2007 5.7osi petrol whining under load

[woodsy01]

I have replaced hi pressure pump as boat was stalling, full of the usual black paint I hear of about Volvo.
cleaned out the entire fuel cell and boat now runs fine BUT, at about 3000 rpm, only under load, I can hear a whining, but only with the engine lid open.Seems to go fine but I'm concerned something is being damaged.
Could it be the lo pressure pump ?
Replaced filter and fuel seems to flow fine to fuel pressure regulator.

 

[alldodge]

If a fuel pump is whining this in most cases caused by a restriction or air getting in. Place a vacuum gauge between the fuel tank and the filter.

Is there any kind of miss at WOT?

 

[Scott Danforth]

other sources of whining could be alternator bearings, idler bearings and low oil in the power steering reservoir.

 

[woodsy01]

thanks for your replies. Not hearing or feeling a miss at all, seems to run fine. I cant tell where the noise is coming from, the hi and lo pressure pumps arent getting even warm. Replaced water pump recently and all bearing felt fine when belt was off, plus its only under load from about 3000 rpm, if it were a bearing it'd be more constant ?
What would I be looking for in the vacuum gauge Alldodge ? do i just cut the main fuel line and install one ? leave it there permanently ?

 

[alldodge]

Place inline using a Tee fitting and you don't want anymore then 1 inch of vacuum. If you get more then that it could be your anti-siphon valve

If there is a restriction, then at WOT there should be a miss

 

[woodsy01]

thanks alldodge, let you know when i get out next

 

[QBhoy]

Hi
does or do it in neutral at 3000 rpm ?

 

[woodsy01]

Hi QBhoy, sorry for delayed reply, its been winter down here and I have out it out ofsight and out of mind. Def not whining in neutral, can rev to 5000 rpm and no noises. Also, no missing, runs nicely to about 5200 rpm.
Just replaced alternator and both hi and lo pressure fuel pumps, FPR screen is clean and even tried a friends one, still a whine at around 3000 rpm and hard to tell where from.
Power steering pump seems fine as do the pulleys, its driving me nuts !!
I cant hear it with the lid down but it worries me because I know its doing it, perhaps it always has and I've only discovered it while running with lid up to keep an eye on my new fuel pump connections etc.
If it were a pulley bearing wouldit not make noise even in neutral, cant see how a load would affect that.
Thank you,