why is my oil pressure gauge twitching around?

[Paladin]

Hi, So I was out on my boat yesterday and although it ran fine, the oil pressure gauges-both on the flybridge and below on the inside helm dash were sometimes their usual settings (about seventy five) but sometimes just dropping to zero or twitching around, or staying at forty for a second then going back up, etc. Very fast twitch, stay there for a few seconds, go to some other number. Sometimes it would stay at the usual place for a five minutes at a time.
I have just changed the oil and filter, and checked it, and have enough.
So, because they both were twitchy I was thinking it wasn't the gauge(s), but maybe the oil pressure sending unit? Or switch? Where are they, and what do you all think? Thanks!

 

[Jensemann23]

Could sound like a Ground failure or sending unit failure. I would try to insert a manual gauge on the engine just to check. The sending unit is located on the lower rear port side mostly.

 

[Paladin]

thanks, yeah, that could be (like an intermittent ground failure).. Is it hard to get to the sending unit for oil pressure? is there an oil switch too down there?

 

[Bob & Sue]

I had a water temp gauge do the same thing it was a corroded pin in the wiring harness at the engine, all I had to do was disconnect it scrape all the corrosin off put back together with dielectric, make sure not to get dielectric on any off the pins it doesn't conduct electricity. I would also try a manual gauge on it.

 

[Old Vet]

my oil gauge did exactly the same thing.....new sending unit cured it....a $30.00 fix

 

[Paladin]

Well, we were right about it being electrical I had a boat mech look at it today, as he was down near the boat and I wasn't, and he said that the nut holding the wire onto the sending unit was barely on the stud, and the wire was of course real loose, so he tightened it down . I am relieved and pretty much think that was it. As always, thanks for the help!

 

[08Dancer380]

I had to read this because this is what happened to my older boat. We got lucky as well and it was the same thing. Quite an easy fix... I thought I'd be shelling out a lot of money for a major issue.

 

[Paladin]

You know, I have had a few vibration related things happen of late. Last month my mechanic found my oil pan bolts and even the drain plug were actually loose to the hand, just from vibration over time I think. I had a small oil leak down there, now fixed.

 

[Old Vet]

Quite an easy fix... I thought I'd be shelling out a lot of money for a major issue.

Yeah....I was ecstatic last year when I found my problem. How often can you get away with a $30 fix on a boat? And THAT'S ALL it cost me last season for repairs of any sort......hope this season is as good.

 

[Bob & Sue]

You know, I have had a few vibration related things happen of late. Last month my mechanic found my oil pan bolts and even the drain plug were actually loose to the hand, just from vibration over time I think. I had a small oil leak down there, now fixed.

I've made it a routine everytime I'm in the bilge to check oil, battery etc I take a couple wrenches and screwdrivers to tighten any loose bolts mostly on clamps and wire connections I can reach you'll be surprised how many clamps loosen up from vibration. Your oil pan bolts shouldn't come loose you may want to remove them one at a time and put some thread locker on them. Any bracket bolts that I find that have come loose I pull out and put some thread locker on them. Use a thread locker that is made to remove bolts with a wrench without heat like Loctite 242.

 

[Paladin]

thanks, good ideas. I like locktite, although I have also used a dab of caulk if that's what happened to be near. Probably doesn't work as well. I do fool around down there and check things, but I wouldn't have thought that oil pan bolts would loosen, unless they weren't put on right to begin with, which is a possibility.. because it's odd that they were all loose..