Water Pump - plastic or metal?

Boro&Beth

Boro&Beth

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Will be replacing the water pump on our mapped S3 over the next few days aswell as cambelt, etc.

Ive searched and read about metal impeller versions. Are these worth fitting over the standard plastic type?
 
I think the general consesus is yes. however i read (I'm sure) on a pistonheads forum the other day, that audi corrected the fault on the plastic ones so that they (the plastic ones) are less likely to fail.

i'd be interested to know if this is true.
 
I have a friend who works for an Audi dealer, might give him a bell in the morning and ask him that. Thanks
 
metal metal metal metal.

I can't tell you how many waterpumps between my friends we have taken apart that have been in several pieces, and are amazed they are still together.

Plastic sucks.
 
My plastic one self destructed. Ive upgraded to metal.
 
Boro&Beth said:
Has anyone had a metal one fail and what sort of mileage did it last?
Click to expand...

Never heard of it. It should be changed same time as the cambelt, so 60k miles or 6 years. I would expect it to easily last this duration.
 
The last one was changed in 2006 at 95k along with the cambelt kit. The car has now done 129k and the water pump is knackered.

Looks like it will be getting another cambelt along with a metal impeller water pump. Should be good for a few years then.
 
audi upgrades
I went for plastic, I actually think a lot of the breakage is done while removing the pump. I quite a tight fit so if you dont pull it out square then you can break it. This Is what I think I did as I found all the bits to rebuild it on the bench.
 
metal everytime.
they do fail or at least I have read stories of one failing, impeller came off the spindle.
but extremely rare compared to the numerous plastic ones that are reported to have disintergrated. as for breakage on fitting/removal, I would say it is possible, but isn't that even more reason to get a metal one?

mine came with the whole housing so that was not an issue.

question: would you buy an oil pump with an plastic interior?
 
fingermouse said:
I went for plastic, I actually think a lot of the breakage is done while removing the pump. I quite a tight fit so if you dont pull it out square then you can break it. This Is what I think I did as I found all the bits to rebuild it on the bench.
Click to expand...

The thing is, they have been breaking when in situ, not when someone has taken it out to inspect it.
 
metal for definit.

My plastic one broke inside and luckly id car parked and ready to do timeing belt...
 
Just had an interesting conversation about the benefits of metal over plastic and apparently the plastic ones fail as the impellers are the weakest link, however, the weakest link of the metal versions are the bearings.

If the plastic version impellers break, the car will start to overheat.

If the metal version bearing fails it can cause engine failure.

If the above is true, there could be alot of people running metal impellers that if not changed at the right intervals, could cause more damage.

Confused!
 
What that means is if you have a plastic one, you have 2 weak points.
The bearing and the impeller.

Basically is it's not swapped out at the right interval the bearing's likely to go regardless of impeller type.

There's no logical reason for sticking with a plastic one if there are metal one's available...

Well one possible is if the impeller is made of cast iron/steel etc then you could have corrosion issues if you dont have enough inhibitor.

Sarah, any ideas what type of metal they are made of?
 
My plastic original one failed at about 35k - looked a right mess. The impellor had become detached from the spindle - the inside looked scratched / burnt.
Metal for me now
 
The reason VAG had plastic impellers fitted on the pump is that they will shatter/break loose if the coolant freezes inside the engine without ruining it by stripping cambelt teeths. With the wheather UK has, i think this is not the case and i would recomend replacing the pump with a high quality MEYLE/KWP one wich have genuine bearings and the stress on the bearings with the metal impeller is minimal...
 
Hi
I dont have a clue which metal it is made of to be fair.......sorry
But I have been using them myself too , but always replace them at timing belt time , mine is just about to have its 3rd one fitted
Sarah
 
S3 Wannabe said:
I think the general consesus is yes. however i read (I'm sure) on a pistonheads forum the other day, that audi corrected the fault on the plastic ones so that they (the plastic ones) are less likely to fail.

i'd be interested to know if this is true.
Click to expand...

I'd take everything written on PH with a big pinch of salt....some proper 'armchair experts' on there. There are a few people who know what they're on about but 99% of posters are just arrogant muppets who get a chubby on over their F reg blue smoke puffing TVR. I only go on there when I fancy an argument with someone :ninja:....
 
A3Tom said:
I'd take everything written on PH with a big pinch of salt....some proper 'armchair experts' on there. There are a few people who know what they're on about but 99% of posters are just arrogant muppets who get a chubby on over their F reg blue smoke puffing TVR. I only go on there when I fancy an argument with someone :ninja:....
Click to expand...

LOL!!!

So to summarize on the above Plastic or Metal, change the pump with any cambelt.
Keep an eye on your temperature gauge (plastic)
Hope the metal impeller doesn't jam and strip your cambelt (metal)
 
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