Water Pressure sensor

Now that's why I joined CSR!! Out today on Pittwater with friends, alarm goes off and smart craft says "water pressure sensor" or similar (several hours later as I'm posting this). We had only been doing about 4 knots and alarm sounds and "guardian" kicked in. Engine temp normal as were all other gauges. I turned engine off to open hatch to inspect but it wouldn't let me start again. Drifted over to a moored yacht and tied off, made some new friends!! But jumped on CSR on my iPhone and found this wealth of information.

After reading this thread while tied off, I disconnected the plug from the sensor. Engine was clearly not overheating. Started fine and we then limped on, sensor disconnected. All gauges remained normal. Got up onto the plane and 10 minutes later at 3600rpm alarm sounds again. Throttle off to 2000rpm alarm stops. Spent a lazy afternoon on a mooring at The Basin and then engine wouldn't start. Reconnected faulty sensor and started fine. 5 minutes later alarm sounds again and guardian kicks in. Stopped, disconnected wires from sensor and started again, away we went, all gauges fine, certainly no overheating issues. Alarm sounds after 10 mins on plane at 3600rpm, throttled back alarm stopped. Didn't interrogate smart craft warning at this point as I was watching the gauges while throttling back and then alarm stopped. We just came home then at a leisurely 2000rpm.

Im hoping this is just the faulty sensor I've now read so much about here but my question is, are these other symptoms consistent with just a faulty sensor? Guardian kicking in, another alarm after running 3600rpm for 10 minutes, not wanting to start again after being off for several hours, mind you when we stopped we turned engine battery off - this might affect restarting if there is some sort of resetting going on once engine is turned on or off. Anyway, any knowledge on this would be greatly appreciated.
 
Installed new sensor today. I started the motor with the old sensor and watched the water pressure gauge start at 0.2 bar and gradually decrease to 0 as the engine warmed up. Even throttling up in neutral didn't get a reading. Then I installed the replacement and reading about 0.1 bar at idle and increasing as I throttle up. Just the way it should. Problem resolved simply and relatively inexpensively thanks to the information on CSR. FWIW I will try to clean the old one and see if I can get it to work as a spare.
 
Last edited:
So I just had my impeller and water pump changed at 100 hrs for PM this spring before commissioning
never a water pressure or temp issue prior to winterization and pump change
mechanic runs boat as part of re commissioning last week (I'm not there )and I'm informed smartcraft takes engine into guardian mode with a Psi fault and smartcraft alarm-I was told engine temp was 157 when guardian kicked in -not sure mechanic got psi reading.
Seems to be a coincidence this occurs right after pump was changed
I flush motor religiously can't imagine a corrosion problem
has to be water pressure sensor issue -right ?
unusual to fail at 100 hrs ?
Is it possible smartcraft needs a master reset after a water pump change ?
thanks for any advise !
 
was the boat on a hose or in the water and he was taking it for a ride? He should of turned the ignition on and looked art the water pressure since it should be at 0 and if it was anything than or over 1lb, the sensor should be replaced. Then he should of started it and watched the pressure rise. He could even rev it up a little(2000 rpm) to see the pressure move up to a few lbs. if the gauge was still at 0 he should check to see if its pumping water. If it is pumping, replace the sensor. If its not pumping I've seen allot of the new style brass water pumps get grooves in the housings due to wear and with a new impeller they don't make a good seal on each other and don't want to suck water (air locked). If thats the case sometimes sanding down the cover smooth will help or you might have to replace the housing.
 
flflatrate said:
was the boat on a hose or in the water and he was taking it for a ride? He should of turned the ignition on and looked art the water pressure since it should be at 0 and if it was anything than or over 1lb, the sensor should be replaced. Then he should of started it and watched the pressure rise. He could even rev it up a little(2000 rpm) to see the pressure move up to a few lbs. if the gauge was still at 0 he should check to see if its pumping water. If it is pumping, replace the sensor. If its not pumping I've seen allot of the new style brass water pumps get grooves in the housings due to wear and with a new impeller they don't make a good seal on each other and don't want to suck water (air locked). If thats the case sometimes sanding down the cover smooth will help or you might have to replace the housing.
Click to expand...

thanks for quick reply.. he ran it down the river.. also, i had the entire pump assembly replaced…brand new.. no grooves….
don’t have answers to the psi question yet.. just find it to be too much of a coincidence this times exactly with new water pump and impeller…
temperature stayed normal under load before guardian kicked in.. seems water is flowing...
 
I would run it and watch the water pressure. If you have a 2011 you probably have an Ec motor which has catylic converters (hopefully I spelt it correctly). Those motors need a little bit more water pressure or you will have that alarm sound when you get on plane. If you run it and get on plane and your water pressure is only A few lbs (like 3-6) the computer wants more pressure so will out it in guardian. If that happens you probably have a water intake restriction (barnacles or seashells inside the drive blocking the intakehose or water intake hose at the transom assembly crushing up which happens in salt water)
 
Those Water Pressure Sensor are junk. I've replaced both of mine within the past year. No overheating. They seem to go out at just the right time!
 
gerryb said:
You'll need a long socket (sorry forgot the exact size), extension bars and possibly a flex socket adapter. You will need to lay on the engine so remove the cover, arrestor and anything else that looks like it may break when yo are on the engine. A mover's blanket folded over several times is a good way to safely lay on the engine in comfort. The sensor should come out rather easily. Might have to warm up the engine a bit if it does not. Be sure to remove the electronic connector first (It can only go in one way).

New sensor will come with red thread sealant on it - if not, you'll need to add some of the red stuff to the thread, just a drop. Might get some water come-out of the opening but not enough to keep you from screwing in the new sensor. Do this by hand if possible or you may ruin the threading!

... And lastly, this is where the little bugger is if you were looking at the back of the engine...
Click to expand...

This post was ages ago but helped me immensely locate the water pressure sensor.

Possible to replace with crescent wrench but highly recommend 1” deep socket.

I was getting the double beep every minute with water pressure sensor fault. Replaced with OEM and all is well again. Crazy the stupid part is $150. The Chinese knockoff is $35 but I don’t want to deal with it again next year.
 
You must log in or register to reply here.

Forum statistics

Threads
113,186
Messages
1,428,177
Members
61,097
Latest member
Mdeluca407
Back
Top