Cummins 5.9 QSB engine temps

[Joe Williams]

Hi – I have a 2007 Sea Ray 360 Sedan bridge with Cummins 5.9 QSB engines w 700 hours. At running rpm’s the engine temps are very close – 183 vs. 179, the manifold temps are off by about 10 degrees and the oil cooler has been off by 143 vs. 123. Should all the readings match, or can there normally be differences? Could I have cooling issues on the engine with the higher readings? Thanks for any feedback.

Topic

[Joe Williams]

Thanks. Will measure them with the laser. May also switch the sensors and see if the temps flip accordingly.

[Philip]

Just a thought but does the actual transmission temperatures vary above the 2500 rpm threshold? Get down there with a laser thermometer with someone driving the boat at 2500+ rpm and shoot the same locations on both transmissions close up and see if the actual transmissions are running at the same temperatures.

[Joe Williams]

Thanks all for you replies. A little more detail / updates about my issues. The engine temps match at all RPM’s and the manifold temps vary by about 2-3 degrees. At 2500 RPM’s my Oil Cooler temps don’t match – port is 136, starboard is 116. That’s where I am concerned. Oil Cooler pressure is even though for both sides. I bought the boat last year and don’t know the service history. It’s a New England boat used for coastal cruising and spends half the year out of the water. Thanks.

[Rob Schepis]

Yes, some history would help ——- how long you have owned it and is this the way it’s been since day one or is this a new development (gradual or sudden)? And, of course, service history…

[Fireisland1]

Mine runs 176 all the way to 2300rpm then from 2300 up it’s 177 .

[Mike Mason]

Mine run 176 even on the vesselview.

[Philip]

What’s the history of th engine, salt/fresh water ops, service history, how long have you owned?

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