Small Change in Operating Temperature

[Doc]

I have recently noticed a 2 degree increase in the operating temperature of my 2000 model Cummins 330 hp engine. This increase coincides with the Cummins Tech changing all my hoses and clamps, off boat cleaning of all heat exchangers and coolers, replacing the coolant circulating pump and the thermostat.


Impeller has 152 hours and it has been 711 hours since I did a minor rebuild on the Sherwood RW pump which was a new cam and wear plates. The pump itself which does not (as I type this ) leak has about 1200 hours.


I have owned this boat for 5.5 years and have added 1120 hours to the meter. Total time now is 2250. The bottom job is less than 60 days old.

The boat's operating temperature at the 1800 rpm cruising speed was always 188 degrees. Now it is 190 degrees and has been for three short cruises.

All that PM should have lowered the temperature I would think.

-- Edited by Doc on Sunday 5th of December 2010 11:45:05 AM

 

[Codger2]

Doc:

I having similar problems with my 330B which I believe is the same model as yours. My temp went from 192 -198 and after checking the gage, thermostat, sender, impeller, etc.
no one has been able to identify the problem. (We've even pulled the end caps on the heat exchanger, rodded them.) The spec says 183-203 is OK but it doesn't explain the rise in temperature. Keep me posted if you figure it out and I'll certainly do the same.

Walt

 

[Marin]

While a long shot, this can happen-- it has on our boat. If in working on your boat's engine the ground and temp sensor wires were removed and reconnected, or even bumped or wiggled in some cases, this can change the resistance--- or eliminate it--- across the connection. This in turn can change the reading of the display connected to it.

 

[Arctic Traveller]

Doc wrote:

I have recently noticed a 2 degree increase in the operating temperature of my 2000 model Cummins 330 hp engine. This increase coincides with the Cummins Tech changing all my hoses and clamps, off boat cleaning of all heat exchangers and coolers, replacing the coolant circulating pump and the thermostat.

New thermostat????* There can be a difference from one to another of even the same rating. * 2 degrees is pretty minimal, probably nothing to worry about, just monitor........Arctic Traveller

*

 

[jleonard]

"There can be a difference from one to another of even the same rating. * 2 degrees is pretty minimal"

And I doubt that the gage acccuracy variation could pick up 2 degrees reliably.
I would say it's a wash.

 

[Carey]

jleonard wrote:

"There can be a difference from one to another of even the same rating. * 2 degrees is pretty minimal"

And I doubt that the gage acccuracy variation could pick up 2 degrees reliably.
I would say it's a wash.

JayIs there any chance you have a little eel grass or other debris blocking your cooling system? If I were boating in the Gulf of Mexico, I'd also be looking for possible buildup of oily matter coating the whole system.


*

 

[jleonard]

"Jay Is there any chance "

You got the wrong guy. I'm a new england boater. No eel grass buldup for me. Hauled out after 6 months in COLD water.

 

[Carey]

jleonard wrote:

"Jay
Is there any chance "

You got the wrong guy. I'm a new england boater. No eel grass buldup for me. Hauled out after 6 months in COLD water.

*

JayThere is eelgrass on the east coast, even a freshwater variety. Not to mention there are all kinds of other debris that could be inhibiting your cooling. Just trying to help you touch all bases. But, maybe I had the wrong guy.

*

 

[Arctic Traveller]

jleonard wrote:

And I doubt that the gage acccuracy variation could pick up 2 degrees reliably.
I would say it's a wash.

I was assuming it was digital, but even then??????* Arctic Traveller

*

 

[FF]

And I doubt that the gage acccuracy variation could pick up 2 degrees reliably.

If you want to KNOW , Murphy will sell you mechanical instruments with YOUR temperature range displayed.