Does a water pump fail more with age or mileage?

It's been 3 years already and I hit 50k miles on the water pump that I already replaced.

Just wondering when these should be replaced? I'm almost at 60k however I drove alot and the pump is only 3 years old

Wondering do they fail more with age or with mileage?

Mileage... You're good until 100k, or until it leaks.

Def mileage, the bearings will wear out and bearing seals will tend to leak.

keep a spare pump in the trunk. no need to get crazy over replacing something that still works perfectly fine

Are most water pump failures for the e46 related to the plastic propeller failing or the seal hardening and a leak developing?

^
- plastic impeller: not many E46 cars came with a water pump that has a plastic impeller.
- seal or gasket leak: not a huge problem since it should give you a plenty of warning.

There's another way the water pumps break:
- pump bearing failure: the problem you should worry about the most. You can consider yourself lucky if you notice the bearing is failing (pump axis wobble, noise, etc.) before it's too late. If you don't, the failed bearing will get you stranded. However, If your car has a mechanical radiator fan, which is bolted onto the water pump, you will get stranded, the fan blades will be shreded, and the flying splinters may cause a lot of additional damage.

So if you have like 140.000 miles on it, it's probably been replaced in the past right? :p I feel like I'm in a driving time bomb If it's been replaced it's probably good another 100k, specially with a newer model pump?

Originally Posted by jporter

So if you have like 140.000 miles on it, it's probably been replaced in the past right? :p I feel like I'm in a driving time bomb If it's been replaced it's probably good another 100k, specially with a newer model pump?

Mine wasn't replaced when I pulled it out at 148k. The bearing and the impeller were still perfect. It was leaking from the O-ring, so I installed a new one.

Replace yours, it may not have been before.

Yeah will do
I just remembered I've got an alarm certificate in the car which states the name of the previous owner. I'm gonna try and give him a call/mail, see what he has done to the car if he still remembers It would be a shame if it was replaced at 100k and I'll just replace it again now at 140k. There is no leak from it at the moment and I'm having no cooling issues but I'm quite afraid the pump will go boom while I'm on the highway

Stewart pump FTW trust on this. Just from looking at the thing it should last 150% longer then the oem and it gives better flow matched with a proper under pulley kit=straight up boss

150% longer than OEM? So, will OP drive his car another 200,000 miles? Because that's where he will break even.

maybe, cant speak for you or him but i joined e46FANATICS because thats how i feel about mine.

Originally Posted by STiGLiTZ

Stewart pump FTW trust on this. Just from looking at the thing it should last 150% longer then the oem and it gives better flow matched with a proper under pulley kit=straight up boss

Lasting 150% longer for 400% the price isn't that good of a deal

Well in another 200K miles, he would be better off just installing another cheaper pump anyway, since a) they cost 1/4 of the Stewart and b) he will have to replace everything else, since they aren't made by Stewart. Just sayin'.

idk something about a plastic impellar spinning all the time just doesnt sit well with me. In addition to the research ive done on the e46 cooling system being the most problematic engine asset, they also come up inconsistent where many can self destruct at 80-90k and some go and additional 50k so i suggest the stewart pump simply for the idea of taking a rather expensive and irreversible variable out of the equation. Because once these cooling systems **** the bed so does your car.

http://www.oembimmerparts.com/BMW_E4...rts_s/1863.htm

not sure where you are shopping but i went through this place and had everything shipped to me in under 24 hours free of cost and when i do the math the oem and the stewart are no where near 400%, so you may want to take a look at the facts bud

Originally Posted by STiGLiTZ

http://www.oembimmerparts.com/BMW_E4...rts_s/1863.htm

not sure where you are shopping but i went through this place and had everything shipped to me in under 24 hours free of cost and when i do the math the oem and the stewart are no where near 400%, so you may want to take a look at the facts bud

300% then. Most places sell the stewarts pump at closer to retail. Still not a good deal all things considered. Expansion tank is a more frequent point of failure - and the Stewart's pump won't help with that.

A composite is not a plastic btw.

Read much bro...never said composite was plastic, meanwhile in reality if you put on your spectacles and refer to the picture i posted the impellar is plastic....der, just like many e46s which have never had this done or have had the dealer do it....der
So as far as being worth it i guess its more of a personal preference if a stock oem water pump can handle 80-130k the stewart can most likely double that and then some.....Just saying if you are that cheap where that critical of a component is where you are going to skimp and cut corners maybe you shouldnt drive a bmw or anything german for that matter

Its probably for the people who go to a mechanic to get their work done. It costs more but you save on labor.

Did all the labor myself when I did my coolant overhaul and prior to, and many across this forum and bimmerfest recommend it esp if you plan on using the uuc under pulley kit to free up some more horses.