Metal or Plastic Impeller?

Discussion in 'KJ General Discussion' started by LONGJEEPOWNER, Jun 19, 2019.

  1. LONGJEEPOWNER

    LONGJEEPOWNER Full Access Member

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    I have to purchase a new water pump for my 2010 Jeep Liberty with a 3.7 cu.in. engine. While on line I see that they make the water pump with a plastic or metal impeller.
    So does the OEM part come in plastic or metal impeller? Which is the better water pump?
    Thanks in advance.
     
  2. turblediesel

    turblediesel memberable

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    I've read plastic impellers can fall apart if the wrong coolant is used. Don't know if it's true.

    Metal impeller pumps are preferred by the CRD crowd because broken water pumps can result in fully destroyed engines.
     
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  3. 04Liberty

    04Liberty Full Access Member

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    Friend of mine blew up a 3.7 and neither he nor the dealer could figure it why it kept overheating til they figured out the plastic impeller was spinning on the shaft (or more accurately the pulley shaft was spinning inside the plastic impeller). Regardless, it caused no coolant to be pumped and killed the engine.
     
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  4. JasonJ

    JasonJ Full Access Member

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    Apparently the repeatedly climbing temperature gauge did not tell them anything? Not sure how people overheat these engines (provided your gauge is working correctly) and not know it... or do it so often that it causes failure.
     
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  5. 04Liberty

    04Liberty Full Access Member

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    It did, the dealer had it trying to figure out what was wrong and gave to back to them just in time to grenade, I'm sure it was already on the way out when they got it back. The water pump thing was found on the post-mortem. They got an engine out of it since that part was directly attributed to the problem aaaaaaand the dealer put it on lol.
     
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  6. JasonJ

    JasonJ Full Access Member

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    Well that turned out for the best, right? Some dealers and private shops take great care not to cause additional damage during their diag or test drives, others... well...
     
  7. 04Liberty

    04Liberty Full Access Member

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    Yes and no lol...free engine yes, but without the vehicle for a good long while. Also it was a Commander, so replacing windshields was a regular thing as well.