power steering noise

[Degree of Freedom]

Thanks in advance.
My 3.0L mercruiser with power steering developed a noise over the winter...fine last trip last year, noisy first trip this year. It's not a grinding noise...kind of hard to explain...my like a whiring/swooshing sound that is always present, but changes pitch and intensity when turning the wheel.

Yes, I have checked the fluid level....no it's not the belts.

Can't get it into the shop until June, so hoping fix it myself.

 

[SIR]

Okay, I'm setting myself up to show my ignorance but I'm not familiar with "power steering" on boats. Do you mean "hydraulic steering"? or does your boat actually use the motor to provide a power steering type function as on a car? I've only had boats with outboards or big boats with deisels so I'm not too familiar with what they are doing in smaller boats with gas inboards. If your checking belts it sounds like it's acutally a power steering system......

If power steering I have no helpful ideas as I'm blissfully ignorant on the topic.

If Hyrdaulic steering. Hydraulic steering is usually pretty bullet proof. The only time I've ever seen noise issues is if you get a bit of crud under the bearings so one of the check valves don't seat well and you get some fluid circulating all the time. This usually has a symptom of either a slight wandering in the steering or the capability to turn the wheel very slowly in one direction or the other with no response from the ram. Usually you only have the problem in one direction as it's a different check valve for each direction so you'd have to have problems with both valves for it to leak each way. I've seen this fixed by flushing the helm repeatedly with hydraulic fluid. Sometimes you can work the grit out other times you hope that you have a serviceable unit as some are sealed and can't be serviced (speaking from expensive experience).

This is not a common problem so I'd be more inclined to look elswhere if you have no issues with the steering performance.

Not sure that helped... but at least I'm going to find out if inboards have power steering

 

[Degree of Freedom]

I'm a little ignorant myself...there's a power steering fluid reservoir that looks identical to what you'd see on a car, and has a belt driven pump...I'll dig my shop manual out of storage and try to figure it out (just moved and all my books are in an unlabled box in the basement).

 

[SIR]

Okay, I'm thinking car now. The concept is similar except a power steering pump is more susceptable to failure than a simple hydraulic helm.

If it's not the belt I'd change the power steering fluid trying to run some fresh fluid thru the pump to dislodge any crud that might be allowing a bypass of the pump. If that didn't work in my truck I'd be thinking about a new pump as there is not much else in the system that it could be....

Best of luck with the patient, hope you can make her better.