Yanmar 4BY Normal Operating Temp

[Spree]

Hi all - I have a 2012 C26 with the Yanmar 4BY-180. I purchased the boat back in October. I’ve always cruised around 3200-3300 RPM and engine temps have consistently been between 195-197 degrees. The last month or so I’ve been noticing the temps climbing incrementally. At the same 3200-3300 RPMs, the engine now runs at 198-199 degrees. It’s not much, but I’m wondering why I’m seeing an increase. Coolant is full and raw water pump is brand new with a brand new impeller. I talked to a mechanic who said it could be a failing thermostat. Has anyone had this issue occur or have any thoughts on what to check?

 

[Kevin Lamont]

Hi all - I have a 2012 C26 with the Yanmar 4BY-180. I purchased the boat back in October. I’ve always cruised around 3200-3300 RPM and engine temps have consistently been between 195-197 degrees. The last month or so I’ve been noticing the temps climbing incrementally. At the same 3200-3300 RPMs, the engine now runs at 198-199 degrees. It’s not much, but I’m wondering why I’m seeing an increase. Coolant is full and raw water pump is brand new with a brand new impeller. I talked to a mechanic who said it could be a failing thermostat. Has anyone had this issue occur or have any thoughts on what to check?

Hello,

Do you know when the last time the heat exchanger was cleaned? There could be an issue with water flow from the engine strainer and or the heat exchanger. It could be possible a thermostat is failing but typically you would see it get hot quick or not get hot at all depending on which way it got stuck. I would make sure all water flow areas are clean of any debris, also may need to have the coolant checked to see if it needs to be serviced. Hope this helps.

Thanks,
Kevin Lamont

 

[rpmerrill]

Has the water temperature you are cruising in gone up.
I'll bet it has.
Not sure about the west coast, but the shallow Chesapeake Bay temperature changes a lot.