Temp range?

JRT

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Feb 14, 2017
2,037
Catalina 310 211 Lake Guntersville, AL
Last year, our first for the 310, my engine temp was rock solid at 170 until we hit high temps in the summer and would go as high as 180. This year so far it is sticking a bit under 180. I've checked the strainer and it is clean. Fresh water boat whole life, 670 hours, water pump up graded and all coolant lines changed out and fresh coolant. Should I care?
 
Mar 6, 2008
1,078
Catalina 1999 C36 MKII #1787 Coyote Point Marina, CA.
That is as high as I would allow for a short period of time. Try cleaning the heat exchanger. Where is your home waters and what is the water temperature measured by you.
 
Nov 18, 2010
2,441
Catalina 310 Hingham, MA
Last year, our first for the 310, my engine temp was rock solid at 170 until we hit high temps in the summer and would go as high as 180. This year so far it is sticking a bit under 180. I've checked the strainer and it is clean. Fresh water boat whole life, 670 hours, water pump up graded and all coolant lines changed out and fresh coolant. Should I care?
How often are you checking the zinc in the heat exchanger? Have you removed the end caps and cleaned it out.
 

JRT

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Feb 14, 2017
2,037
Catalina 310 211 Lake Guntersville, AL
So I haven't done anything with the heat exchanger, so I'm a bad owner. What should I expect for water and process. Of course the intake will be closed but I've not had any guidance on this part of the cooling system. The water temp from the instruments said 68 last time out
 
Dec 16, 2011
257
Catalina 310 Atlantic Highlands
I change the heat exchanger zinc every year, and when I changed the seals and o-rings on the end caps a couple of years ago my running temp dropped 5 degrees and runs very consistently between 160-165. That is saltwater here in the northeast (NJ).
 

JRT

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Feb 14, 2017
2,037
Catalina 310 211 Lake Guntersville, AL
I'd have to order everything for that, is it worth it to just take the end caps off tomorrow and try to clean out as much as possible? Sunday looks like a sail day so would like to still go out.
 
Jan 7, 2014
395
Beneteau 45F5 51551 Port Jefferson
My boat is in salt water, not sure if you use zincs in freshwater. I would also check the exhaust mixer. That's where my problem was, it was completely blocked from calcification. Less likely in fresh water but still possible.
 
Last edited:
Jan 7, 2014
395
Beneteau 45F5 51551 Port Jefferson
Take the end caps off first and see what you see, probably pieces of impeller or anode. You should be using magnesium anodes in fresh water. You have checked the impeller right?
 
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Mar 6, 2008
331
Catalina 310 Scott Creek, VA
my 2003 M-25 xpbc runs around 175-180 in Chesapeake bay summer temps with a new impeller and radiator shop cleaned heat exchanger. Don't worry, go sailing this weekend, then pull the endcaps and check for pieces of zinc or impeller there next week. In a pinch you can invert the gasket and reinstall , then buy a half dozen spares for your spare parts box next time.
 
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KZW

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May 17, 2014
831
Catalina 310 #307 Bluewater Bay, FL
My 2005 M-25 XPBC runs around 175-180 in Choctawhatchee Bay with the water temperature 85+ degrees in the summer.
I put in new heat exchanger gaskets last month and cleaned out the heat exchanger. I check the zinc every month.
 
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Feb 14, 2014
7,400
Hunter 430 Waveland, MS
Should I care?
Yes, but only if the High Temp Alarm sounds. You should test that alarm. Mine has a test button at the helm.
Always keep up with it, but the temperature measurement is not Precise.

How do I know that?
The width of the pointer on a dial and the number of decimals shown on a digital style is the precision.
My Dial pointer width is ±2°F.

The temperature controller on engines is the "thermostat" and they are a very "inexpensive" controller.
Basically ON/OFF control, but can be slightly open in extremely cold water.

Jim...
 

JRT

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Feb 14, 2017
2,037
Catalina 310 211 Lake Guntersville, AL
Thanks, alarm does work, will do some quick checks tomorrow morning before going out.
 
Jun 11, 2004
1,621
Oday 31 Redondo Beach
Precision is ±0.1°F
Inexpensive non contact thermometers are great and I think everyone should have one but don't confuse resolution with accuracy. While the readout may resolve to .1 degree F the accuracy is more like plus or minus 3 degrees F. Not a big deal but something I think a lot of people overlook (and the advertising leads them to do so).

Function\Model GM320 GM550
Resolution 0.1℃/0.1℉
Accuracy:
<0℃ or >25℃: ±1.5℃ or ±1.5%, whichever is greater
0℃~25℃: ±3.0℃ <32℉ or >77℉: ±2.7℉ or ±1.5%, whichever is greater
32℉~77℉: ±4.4℉
 
Dec 25, 2008
1,580
catalina 310 Elk River
Folks we are not checking for Corona Virus here. I'm guessing the variations are more to do with with the thermostat in combination with the sensor and readout.
Do you hear a healthy water gush out your exhaust? If so go sailing.
 
Nov 16, 2012
1,037
Catalina 310, 2000, #31 31 Santa Cruz
Folks we are not checking for Corona Virus here. I'm guessing the variations are more to do with with the thermostat in combination with the sensor and readout.
Do you hear a healthy water gush out your exhaust? If so go sailing.
True, but keeping track of any changes in temperature can give you an indication of possible problems. In that case precision is what you want, not so much accuracy.
 
Jun 8, 2004
2,841
Catalina 320 Dana Point
Got a 140 degree thermostat in mine and if running hard it stays exactly at 140, if running at lesser speeds it runs right under 140. I've got one of those temperature indicator strips on the heat exchanger and it reads 140, might want to use something similar to get an idea of max temp being reached.
 

BillyK

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Jan 24, 2010
502
Catalina 310 Ocean City, NJ
Got a 140 degree thermostat in mine and if running hard it stays exactly at 140, if running at lesser speeds it runs right under 140. I've got one of those temperature indicator strips on the heat exchanger and it reads 140, might want to use something similar to get an idea of max temp being reached.
this is way too cool for these engines.. the manual states that the temp range is between 170-190 degrees.. if you don't allow the engine to reach temp, its not running efficiently and might not be combusting all of the fuel which can lead to other problems later down the road.. this is especially important for diesel engines as it impacts tolerances all over the engine.. valve lash, cylinder clearance, etc....

Mine runs at 175 and will get up to 180 under high load for a duration... sea temperature does not seem to impact the temp of the engine for me up here in the northeast in NJ.