| Author |
Message |
    
Clint Summers
New member
Username: jcs707
Post Number: 2
Registered: 08-2009
| | Posted on Wednesday, October 21, 2009 - 01:37 pm: | 
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79 318s, just replaced impellers, (old ones were intact). Now I have the following issue with one engine: the temp cycles between 140 and 190 only at idle. It takes it about 3 minutes to complete the cycle and then it starts over again.
At any point during the cycle if I throttle up - temp will immediately decrease to 140/150 and stay there. If I return to idle it begins cycling again.
both upper and lower helm gauges do same thing. No temp issues prior to changing the impeller.
/Clint |
PF Herzog
Member
Username: peter_h
Post Number: 4
Registered: 09-2009
| | Posted on Wednesday, October 21, 2009 - 11:26 pm: |
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Double check your new impeller. If you have the standard sherwood raw water pump and your intake is 1-1/4" the impeller should be the 10615. If it's 1" the impeller should be the 09959. If you have closed cooling (FWC) then you might have a dual pocket pump which takes one of each (10615 and 09959).
It's possible to put a 1" impeller in a 1-1/4" pump and it will pump at higher rpms but sporatically at idle.
It could also be a vacuum leak on the suction side of the pump or a sticky thermostat. |
Clint Summers
New member
Username: jcs707
Post Number: 3
Registered: 08-2009
| | Posted on Thursday, October 22, 2009 - 01:28 pm: |
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I watched the mechanic put the impeller in and noted that there was no effort made to keep the fins going in the appropriate direction. At the time I assumed that it didn't matter, but Dave at Hurrikane.com said it absolutely matters. And since this problem didn't exist prior to the new impeller ...it would seem like a logical place to start.
Regarding intake size - good point. When I called emarine and ordered the impeller for 318/Sherwood, ...no question were asked about intake size ...so maybe that's an issue as well.
Thanks for the reply. |
PF Herzog
Member
Username: peter_h
Post Number: 5
Registered: 09-2009
| | Posted on Friday, October 23, 2009 - 02:44 pm: |
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Clint:
Dave knows a lot more than I ever will about marine Chryslers but my experiences suggest that it does not matter which way you initially install the impeller as long as you install the pump body correctly. I tested this on my sherwood G7 pumps by intentionally twisting the impellers into place with the wrong rotation. As soon as I rotated (by hand)the pump pulley in the correct direction, the impeller vanes flipped to the proper direction.
I suggest you remove the thermostat and run the engine to see if the problem persists. Better yet, swap the port and starboard t-stats to see if the problem follows the suspect t-stat. |
Clint Summers
Member
Username: jcs707
Post Number: 4
Registered: 08-2009
| | Posted on Friday, October 23, 2009 - 07:27 pm: |
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Gotcha, ... sounds like a easy next step. |
bobby reid
Member
Username: dodgetkboy78
Post Number: 11
Registered: 10-2009
| | Posted on Saturday, October 24, 2009 - 01:07 pm: |
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My M360 did the same thing, had air in the cooling system. |
Clint Summers
Member
Username: jcs707
Post Number: 5
Registered: 08-2009
| | Posted on Saturday, October 24, 2009 - 01:46 pm: |
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Regarding air in the cooling system, ...was it on the intake side? |
bobby reid
Member
Username: dodgetkboy78
Post Number: 14
Registered: 10-2009
| | Posted on Saturday, October 24, 2009 - 05:19 pm: |
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I'm sure it was all over....... I bled the air out through the bleeder above the thermostat bypass hose. I really am not sure what your question means tho. |
