Engine Sensor ID

Sep 27, 2023
6
Hunter 34 Port Dalhousie
Can anyone help me deterrmine what I need to replace this broken sensor on our engine:

It is located in the front of the engine, I believe it to be one of the water temp sensors?

BrokenSensorLocation2.jpg
EnglinePlacard.jpg
BrokenSensorLocation.jpg
 
Mar 27, 2021
170
Hunter 306 Lake Pepin
That looks to be the coolant temperature sensor. Yanmar part 128275-91340 . You should probably double check that part number though.
 
Sep 27, 2023
6
Hunter 34 Port Dalhousie
Doing a little poking around, I think I need 127610-91350

Can anyone confirm this?
 
Jan 4, 2006
7,012
Hunter 310 West Vancouver, B.C.
It is located in the front of the engine, I believe it to be one of the water temp sensors?
How many water temperature sensors do you have ?

Regardless of how many you have, this one is called a temperature switch (ON/OFF switch) which operates an alarm as opposed to a sensor (thermistor) which would transmit a temperature.

Contact your local Yanmar dealer to ensure you get the correct one as opposed to an automotive temperature switch which may have the wrong temperature setting and thread diameter.
 
Sep 27, 2023
6
Hunter 34 Port Dalhousie
There is another sensor in the pic, at the lower end of the engine block, I assume it to be a oil temp sensor, looks smilar to the broken one, except the broken one is indeed in the coolant line, vs the block. And, yes, they go to idiot lights, so you are probably correct, they are switches vs actual sensors.
 
Jan 4, 2006
7,012
Hunter 310 West Vancouver, B.C.
There is another sensor in the pic, at the lower end of the engine block, I assume it to be a oil temp sensor,
Almost but no cigar.

The lower one is an oil pressure switch which will sense low oil pressure and sound an alarm.

The only reason for being a stickler between "sensor" and "switch" is that I have sensors to read out oil pressure and water temperature which are "nice to have" . However, switches for oil pressure and water temperature are necessary to warn you that you engine is about to self destruct.
 
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Sep 26, 2008
650
Hunter 340 0 Wickford, RI
I have the same engine as you (3GM30F) in my 2000 340.
I will be at my boat this weekend and will check my Yanmar Manual for part numbers and detail of the sensor you are pointing to.
Unless someone else has their manual handy, mine is on the boat.
 

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Sep 26, 2008
650
Hunter 340 0 Wickford, RI
I check my manual this morning, but it doesn’t reference any part number for that sensor. Sorry I couldn’t help, but it does look like others have given you what you need to replace it.
Looking at my engine, it is cramped quarters where the sensor is located. Be careful removing it.