Symptoms of a bad raw water impeller - both engines running hot

Discussion in 'General Maintenance/Repair Questions' started by mrsrobinson, Jun 28, 2022.

  1. Pirate Lady

    Pirate Lady Well-Known Member

    Jun 2, 2020
    Chesapeake Bay, Middle River
    '91 250 Sundancer
    7.4 Bravo 1
    mrsrobinson likes this.
  2. ocgrant

    ocgrant Official Bahamas Boating Ambassador GOLD Sponsor

    Dec 31, 2006
    Miami / Ft Lauderdale
    H2O Therapy
    2006 Sundancer 48
    Novurania 430DL
    Yamaha EX-R
    PADI Divemaster
    Raymarine Electronics
    Cummins QSC 540's
    Maybe you can get one of those guys in a smaller boat to back in and out of your slip a few times to do some “dredging” during a tidal change. Just using the boat a lot in a shallow slip will move a lot of silt and sand.
     
  3. mrsrobinson

    mrsrobinson Well-Known Member SILVER Sponsor

    Mar 9, 2006
    Virginia, USA
    2001 Sea Ray 380DA
    3126 purring CATs
    The slip is ok. It's once I'm out of the slip and navigating the creek channel to the river, the water is low.
     
  4. The Bill Collector

    The Bill Collector Well-Known Member GOLD Sponsor

    Jun 2, 2008
    Tacoma, WA
    1998 450 Sundancer, Achilles dinghy w/15hp
    3126 Cat's
    I'm sure you are aware but dead idle is the best as any increase in speed causes your stern to drop down...
     
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  5. mrsrobinson

    mrsrobinson Well-Known Member SILVER Sponsor

    Mar 9, 2006
    Virginia, USA
    2001 Sea Ray 380DA
    3126 purring CATs
    Yep, I idled all the way out to the river Saturday
     
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  6. The Bill Collector

    The Bill Collector Well-Known Member GOLD Sponsor

    Jun 2, 2008
    Tacoma, WA
    1998 450 Sundancer, Achilles dinghy w/15hp
    3126 Cat's
    Thank you for being kind with your reply, I certainly didn't want to insult your intelligence... This site is here for us to help, encourage and support each other, some days it works and other days not so much.
     
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  7. mrsrobinson

    mrsrobinson Well-Known Member SILVER Sponsor

    Mar 9, 2006
    Virginia, USA
    2001 Sea Ray 380DA
    3126 purring CATs
     
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  8. mrsrobinson

    mrsrobinson Well-Known Member SILVER Sponsor

    Mar 9, 2006
    Virginia, USA
    2001 Sea Ray 380DA
    3126 purring CATs
    PXL_20220701_153256106.jpg PXL_20220701_160929041.jpg PXL_20220701_153302069.jpg Starboard motor, looks pretty darn clean to me, couple small bits of impeller that I pulled off.

    PXL_20220701_150646478.jpg PXL_20220701_150628921.jpg

    Pulled the strainer again and it's half full of mud again
    PXL_20220701_151417846.jpg

    Impeller looks good i think
     
    Last edited: Jul 5, 2022
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  9. dwna1a

    dwna1a Well-Known Member PLATINUM Sponsor

    Apr 23, 2012
    James River
    88 Weekender 300 "Seahorse"
    Twins 350
    So now you know the mud is before the strainer. Intake, seacock, and hose
     
  10. mrsrobinson

    mrsrobinson Well-Known Member SILVER Sponsor

    Mar 9, 2006
    Virginia, USA
    2001 Sea Ray 380DA
    3126 purring CATs
    Actually after further inspected two of the fins on the impeller were contorted and twisted very bad, mechanic here said there's no way it could pull water well.
     
  11. mrsrobinson

    mrsrobinson Well-Known Member SILVER Sponsor

    Mar 9, 2006
    Virginia, USA
    2001 Sea Ray 380DA
    3126 purring CATs
  12. The Bill Collector

    The Bill Collector Well-Known Member GOLD Sponsor

    Jun 2, 2008
    Tacoma, WA
    1998 450 Sundancer, Achilles dinghy w/15hp
    3126 Cat's
    My impellers are inspected annually and replaced regardless of condition every other year.
     
  13. mrsrobinson

    mrsrobinson Well-Known Member SILVER Sponsor

    Mar 9, 2006
    Virginia, USA
    2001 Sea Ray 380DA
    3126 purring CATs
    Last edited: Jul 1, 2022
  14. Pirate Lady

    Pirate Lady Well-Known Member

    Jun 2, 2020
    Chesapeake Bay, Middle River
    '91 250 Sundancer
    7.4 Bravo 1
    Port looks like my piss stream when I was young, starboard looks like now, all over the place.
     
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  15. dwna1a

    dwna1a Well-Known Member PLATINUM Sponsor

    Apr 23, 2012
    James River
    88 Weekender 300 "Seahorse"
    Twins 350
  16. dwna1a

    dwna1a Well-Known Member PLATINUM Sponsor

    Apr 23, 2012
    James River
    88 Weekender 300 "Seahorse"
    Twins 350
    Reinforced rubber hose? I took a dental flush syringe and put soap between the hose and fiberglass then just kept at it. It took putting downward pressure on the hose to get it freed. I don’t have Cats and my hoses are long.
     
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  17. ttmott

    ttmott PhD in OCD TECHNICAL Contributor GOLD Sponsor

    Apr 3, 2012
    Space Coast Florida
    2006 52 Sedan Bridge
    Cummins QSM11
    I thought it easier to remove the entire pump on the starboard side to replace the impeller. You can do all that from aft of the engine; there was plenty enough room for me to get in there on the 400DA. If I remember the gasket was metal and reusable.
     
  18. mrsrobinson

    mrsrobinson Well-Known Member SILVER Sponsor

    Mar 9, 2006
    Virginia, USA
    2001 Sea Ray 380DA
    3126 purring CATs
    Thanks @dwna1a, I may try that, I bought some spray lubricant as well, my main concern is cracking the fiberglass tubes.

    @ttmott I was wondering about that, I'm 6 ft 3 in, I think I can get in front (aft like you said) of that engine. That's the generator side as well.

    I kept both engines running at 2000 RPMs for about 15 minutes. The starboard one, which still has the old impeller, did run about 10 degrees hotter at the gauge at the helm. Both stayed at about 170°

    The port impeller, the one I replaced, looked to be in great condition overall wear wise, though two of the fins were twisted and contorted. Couple of mechanics at the dock said they've never seen one look like that. The only time they've seen something close is on a boat that sat for a while.

    I have a laser temperature gun on the boat, where should I shoot it on these engines to get a true temp?
     
  19. mrsrobinson

    mrsrobinson Well-Known Member SILVER Sponsor

    Mar 9, 2006
    Virginia, USA
    2001 Sea Ray 380DA
    3126 purring CATs
    Took a look at taking the pump off, looked easier to get the exhaust hoses off, which took a while but I got them off.

    Now I cannot get the impeller off, the bolt got it most of the way out but it's really jammed in there.

    PXL_20220702_134147291.jpg PXL_20220702_134133059.jpg
     
  20. dwna1a

    dwna1a Well-Known Member PLATINUM Sponsor

    Apr 23, 2012
    James River
    88 Weekender 300 "Seahorse"
    Twins 350
    Soak it in JB Blaster and let it sit while you cool off and have a drink, then try again
     

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