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Topic: Diagnosing overheating Cummins 8.3 (Read 420 times) previous topic - next topic

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Diagnosing overheating Cummins 8.3
Hot day driving, feels sluggish, oil pressure dancing around, and the temperature alarm starts to go off! My response was to slow down, manage revs in reasonable range, go easy on rises, and talk nice to the wee beasty since we only had about 5...

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Re: Diagnosing overheating Cummins 8.3
Reply #1
Found this on Beamalarm.com

Coolant Temperature Troubleshooting Flowchart

Probably not very useful, now that I look at it...

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Re: Diagnosing overheating Cummins 8.3
Reply #2
Random ideas:
Is the water pump pulley turning?
Any water leaking from the water pump "weep hole"?
Any weird sound coming from the water pump?
Is the oil level OK in your hydraulic fan pump oil reservoir?
How long since you changed the filters in the...

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Re: Diagnosing overheating Cummins 8.3
Reply #3
T stat not opening.  Use the heat gun and see how far the heat travels into the radiator.   Just the top hose hot, without warming the bottom hose, means that the Stat is closed.

  • bbeane
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Re: Diagnosing overheating Cummins 8.3
Reply #4
If it where me I would wash the radiator and change air cooler out carefully with a water hose from the motor side if you ca get to it . If the thermostat has not been replaced recently I would replace it with the proper one from Cummins based on...

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  • John44
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Re: Diagnosing overheating Cummins 8.3
Reply #5
Try blowing the radiator out with air,may be dirty,do you not have a overflo tank,if you do you should see alevel in it,no need to remove cap.Is engine oil level good,is the valve by the coolant filter open?,is the air filter clean and not...

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Re: Diagnosing overheating Cummins 8.3
Reply #6
 Is this something new? Has your temp gauge been normal or any unusual readings on hills, flat, etc? What is "oil pressure dancing around"? When did you last check the engine oil level? Oil pressure may be low at idle but should be stable at...

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  • Twig
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Re: Diagnosing overheating Cummins 8.3
Reply #7
That engine has 2 thermostats. Easy to replace, you don't have to drain too much coolant. I would start there. When you add the coolant back in leave the filter loose and when the coolant starts to flow out the filter tighten it and complete the...

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  • John44
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Re: Diagnosing overheating Cummins 8.3
Reply #8
Some of the 8.3 only use one thermostat,go by your serial number.

Re: Diagnosing overheating Cummins 8.3
Reply #9
Best to use your engine serial number and the Cummins Quick Serve.
Ours only has one thermostat. ('94 - 8.3 )

  • Twig
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Re: Diagnosing overheating Cummins 8.3
Reply #10
Doesn't really matter. I would replace the thermostat(s). Once the housing is off, you'll know. Mine has 2.

Re: Diagnosing overheating Cummins 8.3
Reply #11
woody-  you might pull the water pump and make sure that the hose behind the water pump is not collapsing from the suction.  The hose should have a support wire coil in it. My hose was replaced but the mechanic did not put the wire coil back in...

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Re: Diagnosing overheating Cummins 8.3
Reply #12
So far I have replaced the coolant filter (and only after I had scrambled to screw the new one in did I discover the stop-cock tab on the fitting just in-board of the filter, that would have saved bit of coolant.! I am going to be really smart...

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  • John44
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Re: Diagnosing overheating Cummins 8.3
Reply #13
Reseach your air filter on the forum and make sure which one you have,some of us have the one that filters from the inside so the
outside will look clean,check your housing for a part number,should be a Donaldson housing.

Re: Diagnosing overheating Cummins 8.3
Reply #14
Put your serial number into cummins quick serve and it will have a drawing with part numbers for thermostat, seal, and housing gasket. When I went to local Cummins parts counter he did not order the seal or gaskets. I called after discovering no...

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