Coolant - How hot is normal

[River Bank]

Evening Tugnuts

Happy New Year!

I've been worried about the temperature of my R25 Yanmar (150 HP) engine's coolant.
It has been running between 170 and 190 degrees F.
170 F when idling at 1200 rpm for instance and as high as 190 F when underway at 7 knots.
What is a normal temp that I should expect?

Bob

 

[Barry Cohen]

Sounds about right.

 

[wefings]

Agree,that's within spec. 195 at fast cruise is fine . 200 is still below alarm threshold.
Marc

 

[River Bank]

Thanks for your replies. Going out for a spin in the harbour and I won't be staring at that temperature gauge wondering if my coolant will be boiling away before I get back to port.

Happy New Year, Bob

 

[PhilR]

Bob, My Yanmar 180 HP runs at 195 deg. at +/- 8 knts and 205 deg. at 15 knts. The alarm sounds at around 225 deg. The Yanmar is a rebranded BMW diesel, and my turbocharged BMW auto engine runs around 240 deg. The combination of high RPMs and turbochargers means high operating temperatures.

Phil

 

[HRowland]

The thermostat in our BY2 series engines starts to open at 190F and is not fully open until 205F. Modern engines are designed to run hotter to help meet EPA emission requirements.

Howard