Water pump consensus? Metal/Plastic---it doesnt matter

[B72011]

Whats the opinion of the group on this?
I ordered the 034 Timing Belt kit--it came with an aftermarket plastic impeller water pump.
I know Audi engineered a plastic one--probably for a reason----could be to save a dollar and a cent---I dunno. Maybe other reasons?
I know the Audi OEM one is plastic. Should I send back and get a metal one to install?
My first thought is yeah, second is nah, I'll be changing out this thing in 75K miles so screw it.
Just make sure they do a full flush with distilled water and new coolant and call it a day?

[shiro1745]

There's a whole theory on the plastic impeller on Blauparts.com
They have a video explaining why a plastic impeller is better. I got the plastic one too and I kind of feel sorry now, just a personal preference.

But I wouldn't worry too much you should be fine with a plastic one.

[B72011]

Interesting stuff. Looks like the new plastic is a better choice. Some of the shit Audi does makes the head shake--but the new plastic looks like it will easily do its thing--failure of the bearing is a most likely fail than impeller issues.

http://www.blauparts.com/audi_water_...ntroversy.html

[typeslone]

Being in the industry at the dealer level, specifically VW and Audi, for just about a decade now, I could write a novel on this topic. I won't though, run whatever style pump you feel comfortable with. A water pump can still fail no matter what impeller you have. My B7 has a metal impeller pump, my vr6 drag car has an oem plastic pump. Any oem or oe equivalent pump, regardless of the impeller, should last you 100K miles. If you are changing your timing belt every 80K, then it shouldn't be an issue using the plastic impeller. The water pumps today are manufactured with better quality parts than the ones from the the early B5 and Mk4 vag days when they failed left and right. I have sold thousands of reman'd oem plastic impeller pumps and less than 1% of them have failed while in service. I will say on top of the page the blauparts has about plastic impellers, the bean counters at corporate also have a large say in why plastic is used for a lot of these parts.

The same goes with plastic coolant flanges and what not. The vr6 guys like to spend big money on metal "crack pipes" for their coolant system, hell I have one on my car. But the truth is the oem plastic coolant pipe is dirt cheap and like the original factory one will most likely last 100K miles. I also don't believe in changing cam and crank seals, "while your in there" on a timing belt job. Why disturb them if they aren't leaking. Sorry, I am just ranting now, happens when you become a grumpy old parts guy haha.

So it is your choice fellow 'ziner.

[b6onboost]

Agreed with everything but this....

They often do leak somewhat by the time people do the Timing Belt job. They're such inexpensive parts and its much easier to just do them there. Much cheaper too if you're paying someone to do the TB job. Just preventative maintenance that reduces future headaches. Same reason we change the TB/waterpump at 75k when can certainly last longer.

I also don't believe in changing cam and crank seals, "while your in there" on a timing belt job. Why disturb them if they aren't leaking.

[typeslone]

Agreed with everything but this....

They often do leak somewhat by the time people do the Timing Belt job. They're such inexpensive parts and its much easier to just do them there. Much cheaper too if you're paying someone to do the TB job. Just preventative maintenance that reduces future headaches. Same reason we change the TB/waterpump at 75k when can certainly last longer.

I think I am just jaded from seeing so many "enthusiasts" and "DIY'ers" fail to install the seal correctly, just to have it leak when the og seal was still leak free. You are correct though, they are very inexpensive and if you are paying for labor of a timing belt job, those are essentially freebies while the mechanic is in there.

[B72011]

Thanks for the responses guys on this and everything else that you contribute to the community. I love this place.