Autopilot rattling noise (Garmin)

[Rocky Lou]

I thought there was something inside the helm loose and ratting, but, after a couple calls heard that it's likely air in the autopilot hydraulic system.

When I checked, with the auto pilot off, the fluid level went up to full. I got a hold of Garman tech-support who said likely there needs to be a bleeding of the steering, then the valve, using a pressure device. I had initially called him to find out what type of fluid to add, but, it doesn't appear to need any.

Since I won't likely be heading into a service facility soon and, other than the rattle, autopilot seems to work fine, I'm wondering if anyone encountered a similar issue and found resolution?

 

[Shano]

Our auto pilot will make a knocking sound when we are going very slow and making a hard turn. This happens when we are using our 25 hp kicker and we are trolling. The sound comes right from the pump which on our boat is in the starboard lazerette. The pump is telling me that the rudder is hard over and still not making it to the heading so it is allowing fluid to bypass making the knocking sound. If I straighten out a bit or increase speed then the autopilot will catch up. At what speed does your autopilot make the noises?

 

[Rocky Lou]

I've noticed the 'rattle' at the helm while trolling. I'm typically trolling on one of the two 300hp OBs with speed roughly 2 knots. The moment that I switch on AutoPilot, the rattle starts. If I move the steering wheel, the noise may go away for a short while. At least, i know for certain that AP is causing the noice. I have not, so far, had any issues holding course. However, the noise is loud enough that I usually switch off AP for peace and quiet.

I have not noticed the noise at higher speeds but that may be due to engine masking. It's an interesting question. I will check on Thursday when I'm on the boat and report back. I'll be installing newly arrived down riggers that, sadly, sat in quarantine, in my garage, like many items these challenging days. I will also check to see if there is noise coming from the pump. Are you saying that you do NOT have noise coming from the wheel?

 

[Shano]

We do not have any noise coming from the wheel, our rattling noise clearly comes from the AP pump. Your situation seems different. Maybe the hydraulc lines coming from the helm are rattling when the AP is switched on?

 

[Rocky Lou]

I've been out a few times running AP and the rattling noise is at 'slow speeds' only. Once I increase speed to say, 6mph+ the rattling noise goes away. If I go into the head and pull the mirror open to expose the lines connected to the steering wheel, I can hear the noise there easily. Guessing, it sounds like air in the system...as the Garmin Tech suggested (that the steering and value needed bleeding). Bleeding lines is not something I know how to do, so it will have to wait for a service tech or someone sends a link to a DIY video that convinces me to take a shot.

 

[Ralf H]

Hi all,

Quick chime in to mention that hearing a bit of a ticking or rattling noise can be normal at lower speeds. We see this occasionally on boats as well during our factory pre-shipping tests, and these boats are properly bled at that time. The sound will go away once you begin to increase speed, as you have found. You should be fine, but please let us know if you have any additional questions.

Thanks!

 

[iggy]

Hi all,

Quick chime in to mention that hearing a bit of a ticking or rattling noise can be normal at lower speeds. We see this occasionally on boats as well during our factory pre-shipping tests, and these boats are properly bled at that time. The sound will go away once you begin to increase speed, as you have found. You should be fine, but please let us know if you have any additional questions.

Thanks!

Ralf,

Please correct me if am wrong. This noise is due because the boat in question is not turning fast enough at slow speeds. So the pump (more so the AP computer) keeps trying to make turn by giving a hard port or starboard rudder. Yes?

 

[Ralf H]

Hi Iggy,

Yes, this does happen when the a/p is switched on and you are not making headway, or are doing so very slowly. The constant correction that the a/p may need to make to fight against wind and currents at lower speed will cause this to occur. It will be at its worst when you are stopped and still have the a/p engaged on a particular heading that isn't the exact same as the direction the boat is pointing. This may even cause the system to throw a pump stall fault on the a/p screen. Happens to the best of us. I'll admit to having docked and forgotten to turn heading hold off once or twice 😀

 

[sweet Vidalia]

Hello all, can anyone help me with a problem I'm having with my auto pilot on myC-28.When I engauge the auto pilot the screen lights a warning that the hydraulic pump stalled.
Any advice would be appreciated.

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