Water Pump-Composite or Metal Impeller

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Metal for sure, never had a good thing come long term from plastic/composite impellers. Will also give you headache overheating issues in the future if the impeller is slipping on and off the driving shaft.
 
Metal is preferred but don't buy a bottom of the barrel aftermarket water pump because it has a metal impeller. Most OEM water pumps have plastic impellers and in a well maintained system should not have any issues.

Even metal impellers can fail too.
 
Originally Posted By: Kibitoshin
Metal is preferred but don't buy a bottom of the barrel aftermarket water pump because it has a metal impeller. Most OEM water pumps have plastic impellers and in a well maintained system should not have any issues.

Even metal impellers can fail too.

Yep - it's how well maintained the cooling system is that will dictate how long a water pump will last. Coolant pH and chemistry(sticking to the same formulation for service or topping off) matter a lot. If you own a diesel, this is even more vital.
 
If you have something that doesn't use HOAT type coolant, a composite one might not hold up. I would get something OE quality.
 
Anyone who willfully chooses a composite impeller pump to a metal one absolutely deserves it. Unfortunately, most people never make this choice and still suffer the consequences.
 
For the chrysler 3.7 i’ve heard people say to stick with the mopar plastic impeller.
 
What engine/vehicle?

or just looking for general info?
 
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The impellers and shafts are splined press fits. I wouldn't want plastic, if I had a choice. When you sell a pump with a plastic impeller, you're saying to the customer. Its OK , the bearing or the packing will fail first.
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Originally Posted By: Kage860
For the chrysler 3.7 i’ve heard people say to stick with the mopar plastic impeller.


That's what OE is and what I still use. I think whoever said it's coolant that matters is spot on.
 
Maybe call it intuition, but my sense is that a composite impeller will undergo only so many heat-up / cool-down cycles before fractures develop. The Duratec V6 Ford / Mercury from the Contour / Mystique of a number of years ago suffered waterpump failure / overheating (it being an aluminum heads / aluminum block engine) when the OEM plastic impeller started spinning freely on its shaft, or when the impeller grenaded. I did not let it come to that... rather, I pre-emptively replaced it with a metal impeller jobber water pump...
 
Originally Posted By: Rand
What engine/vehicle?

or just looking for general info?


Both. Pump is for Porsche. OE (and replacement) is composite. Metal is available. These cars are known for early pump failures. Recommend replacement at 30k miles ($$$) with OE.
 
Originally Posted By: willbur
Both. Pump is for Porsche. OE (and replacement) is composite. Metal is available. These cars are known for early pump failures. Recommend replacement at 30k miles ($$$) with OE.

Just use the Graf pump. Used their pumps on VW/Audi/Porsche/BMW since I've been wrenching and never had an issue. For $95 you can't go wrong, and it is a cast impeller.
 
Originally Posted By: rooflessVW
Originally Posted By: willbur
Both. Pump is for Porsche. OE (and replacement) is composite. Metal is available. These cars are known for early pump failures. Recommend replacement at 30k miles ($$$) with OE.

Just use the Graf pump. Used their pumps on VW/Audi/Porsche/BMW since I've been wrenching and never had an issue. For $95 you can't go wrong, and it is a cast impeller.


Thank you Roofless-
can you provide a supplier for Graf? I searched for Graf but no pump came up for this vehicle. Looks like they don't make em for Porsche.
 
Originally Posted By: willbur
Originally Posted By: rooflessVW
Originally Posted By: willbur
Both. Pump is for Porsche. OE (and replacement) is composite. Metal is available. These cars are known for early pump failures. Recommend replacement at 30k miles ($$$) with OE.

Just use the Graf pump. Used their pumps on VW/Audi/Porsche/BMW since I've been wrenching and never had an issue. For $95 you can't go wrong, and it is a cast impeller.

Thank you Roofless-
can you provide a supplier for Graf? I searched for Graf but no pump came up for this vehicle. Looks like they don't make em for Porsche.

Which Porsche? Pelican Parts has them in stock for the 986/996.
 
Originally Posted By: rooflessVW
Originally Posted By: willbur
Both. Pump is for Porsche. OE (and replacement) is composite. Metal is available. These cars are known for early pump failures. Recommend replacement at 30k miles ($$$) with OE.

Just use the Graf pump. Used their pumps on VW/Audi/Porsche/BMW since I've been wrenching and never had an issue. For $95 you can't go wrong, and it is a cast impeller.


Good pumps, Hepu is also good. VW uses some plastic impellers that are notorious for early failure, a quality metal one takes care of it until the next T belt change.
FCP Euro has them for many German cars.
 
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