4.8is Metal Cooling System Parts?

[nick325xit 5spd]

Originally Posted by Aleman

Plastic weakens with every heating cycle. Plastic inside my water pump makes me the most uneasy. Looking around my engine bay, I'm happy to see the coolant pipes are metal or rubber hoses. I've had some expensive and inconvenient problems with the plastic cooling system on my Mini Cooper, so looking to harden the systems in all my cars if possible.

Has anyone had an issue with a broken water pump due to cracked plastic parts?

That's why you just define an expected lifetime and replace. Metal parts are not failure free.

[LA02MAX]

Originally Posted by nick325xit 5spd

That's why you just define an expected lifetime and replace. Metal parts are not failure free.

+1. The plastic impeller didn't fail when my water pump went out. It was the bearing.

[BigBody]

Originally Posted by LA02MAX

+1. The plastic impeller didn't fail when my water pump went out. It was the bearing.

Same here. Impeller was fine.

Originally Posted by aureliusmax

don't even bother with aftermarket water pumps that are metal impellars. i tried the URO unit twice, both times it failed within 5 minutes and cost too much labour/return shipping more than it would be just to pay more and get the plastic OE part.

one of the contributing factors that cause reduced life of the plastic cooling system is the original thermostat that runs over 100deg celcius. you need to replace that piece of trash with a 90 degree thermostat, all the seals in the engine will last longer along with the coolant hoses. i can share a vendor that makes one, that i have installed and used if youre interested.

third, you should lightly coat all good condition hose rubber with AT-205 in a spray bottle to keep them supple.

fourth, buy a pre-assembled viton oring kit and replace all the cooling hose o-rings - which are a failure point. they have them on ebay, if you want i can share the vendor. with this, you should also buy a PTFE water-safe grease (super lube) to coat the orings with during installation.

fifth, these aftermarket cooler expansion tanks are chinese garbage. I had a new one crack open within 90 days.

I replaced my WP with Hepu, from FCPeuro, exactly 2 years ago. Metal impeller, and no problems, knock on wood.