Does a water pump fail more with age or mileage?

This was the noise my car had when the water pump bearing was going bad. I replaced all of the pulleys and belts thinking it was the problem and it still made the noise. Another sign of the pump going bad was one day I inspected the ET and found the coolant level was low. Turns out, it was leaking at the O-Ring and had lots of chalky white residue at the bottom near the weep hole. The pump only had 60k miles on it.

Originally Posted by STiGLiTZ

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.

i can see the value of taking something out of an equation that you find very troublesome. makes sense.
cooling system has no instant damage to the engine or car if a component fails.

Originally Posted by STiGLiTZ

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

i think TerraPhantm was pointing out the "composite" impellars used in the bmw water pumps now are a material that is not to be confused with plastic although somewhat similar.
i doubt he is cheap since our M3 water pumps are hundreds more than a non-M and much better designed.

Originally Posted by STiGLiTZ

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.

why especially if you're using undrive pulleys, is this for the theory that it won't pump as much? flow is not an issue with the E46 cooling system. i have never heard of one person posting that their cooling system performed less than needed when using an underdrive pulley kit.

Change your pump every 75,000 miles with an OE or OE-equivalent. If your pump is old but has few miles, whether or not you should replace it with a new pump will come down to how lucky you feel.

Periodically check your pump for play by removing the belts and fans. But at that point, you just might as well replace the pump. Keep in mind once you remove a pump that's been in place for years, you usually will destroy the seal.

So have new seals on hand if you plan to re-use a pump. No matter how robust a pump is, it's still a good idea to replace the seals while you're in there replacing the rest of the components. (like for example if you ran a "lifetime" stewart)

Stewart pump gets more flow from 3000 rpm upward vs the oem, and in all honesty everyone just calls it plastic more of just a habit to dumb it down rather then have to break it down for the average retard that wouldnt understand composites can be either engineered or natural materials combined through a casting process and im almost posative the older e46 water pumps where composed of petroleum based product maybe not entirely but enough for the majority to be considered plastic.


cooling system has no instant damage to the engine or car if a component fails.
^ as far as that though i couldnt disagree more our coolant systems are eniterly composed of components that run interdependent on one another, belt snaps youre toast, pulley seizes youre toast, water pump fails yore toast, any one component in the system fails it will have catastrophic failure if not instantly pretty damn soon

oh and FYI an under pulley kit causes the outer diameter of belt driven wheels to be reduced allowing FASTER spinning so combined with increased flow from the high flow bullet proof water pump i rest my case....not rocket science dude, now if you want to talk about that get out your crayons and yellow note pad so you can take notes

The composite impeller on the E46 water pumps (that ALL E46's came with) is not the failure point. This part outlasts the life of the bearings. What I have read that happens is that the bearings start to make noise and the seals leak coolant. For an automatic, it can cause the clutch fan to vibrate and it will blow the fan up eventually or destroy the plastic pulley. The only impellers that fail are on E36 generation BMWs and some other models from that period. The impellers that fail on E46s likely have 150K miles on them and over a decade of age. You shouldn't drive a water pump past 100K, just like any other brand (Honda, Toyota, GM, Ford).

Most cars (all brands) get a new water pump at 100K miles when they have their timing belt replaced. They do this because it is easy to do once you have all those parts taken out for the timing belt. BMW's "fail" because owners don't replace them with the belts at any interval. It is so easy to replace, that it never gets replaced on any other service. It is an overlooked item that is REAL maintenance for any car. We don't have a timing belt, so there is no "might as well do the WP too" mentality.

Just get an OEM water pump (Saleri brand) and be happy. It will still have the "plastic" impeller, but the bearings will be new and you will save money over that Stewart pump. Honestly, the Stewart pump is over compensating and it is over engineered. Water flow increase is not necessary.

Originally Posted by STiGLiTZ

oh and FYI an under pulley kit causes the outer diameter of belt driven wheels to be reduced allowing FASTER spinning so combined with increased flow from the high flow bullet proof water pump i rest my case....not rocket science dude, now if you want to talk about that get out your crayons and yellow note pad so you can take notes

An under drive pulley, if it is actually under drive, would need to be larger diameter. This would reduce the tension applied to the belt and reduce the RPM of the part being turned. Less belt tension is less parasitic drag on the engine. If companies are selling "under drive" kits with smaller diameter pulleys, then they are doing exactly the opposite of reducing parasitic drag. Decreasing pulley size will increase the force required to turn the given pulley, and for any given RPM, the viscous (PSP or WP) or electromagnetic drag (for an alternator) would be increased. I think you might be the one who needs to take out your notebook.

Originally Posted by STiGLiTZ

cooling system has no instant damage to the engine or car if a component fails.
^ as far as that though i couldnt disagree more our coolant systems are eniterly composed of components that run interdependent on one another, belt snaps youre toast, pulley seizes youre toast, water pump fails yore toast, any one component in the system fails it will have catastrophic failure if not instantly pretty damn soon

the cooling system is not like when a timing belt breaks. there is no instant damage or immediate damage.
there were some 5 million E46s made in their run and if when a cooling part broke in any of these according to you each of them would have a catastrophic failure. this is not the case! people turn the engine off in a timely manner when either one of up to three gauges/lights activate allerting the driver to pull over and shut down. or they can see steam or feel the belt not driving the ps.

sure the aluminum head is sensitive when over heated but this is nothing like when a timing belt breaks.

Originally Posted by STiGLiTZ

oh and FYI an under pulley kit causes the outer diameter of belt driven wheels to be reduced allowing FASTER spinning so combined with increased flow from the high flow bullet proof water pump i rest my case....not rocket science dude, now if you want to talk about that get out your crayons and yellow note pad so you can take notes

i love when the newbie "know it alls" don't know jack. or in this case.."dude get out your crayons and yellow note pad because this non-rocket science is way above your level of knowledge".

underdrive pulleys like the UUC turn the water pump and the power steering pump SLOWER, not Faster the pulleys are larger and don't turn as much as stock ones..thus "underdriving" them.

now talk more out your pie hole in a rude manner towards members here while we all read it and laugh at how foolish and ignorant to the topic you are.

Originally Posted by adaseb

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?

In my experience its generally the seal around the shaft that goes on a water pump. A few things can affect the life time of the seal. Extremes of temperature change, coolant quality for example. Mileage is one consideration but not the only one. You say you are on your second pump in 50K. I think you must have had a dodgy pump to begin with because that's a bit extreme. I had 140K on my first E36 pump and the replacement was still ok when I got rid of it at 250K. My E46 has 108K on the original pump. I live in relatively mild climate and drive easy. Coolant is to spec.

Originally Posted by Alex323Ci

the cooling system is not like when a timing belt breaks. there is no instant damage or immediate damage.
there were some 5 million E46s made in their run and if when a cooling part broke in any of these according to you each of them would have a catastrophic failure. this is not the case! people turn the engine off in a timely manner when either one of up to three gauges/lights activate allerting the driver to pull over and shut down. or they can see steam or feel the belt not driving the ps.

sure the aluminum head is sensitive when over heated but this is nothing like when a timing belt breaks.

the process in which the engine destroys it self isn't the same, sure, but the end result is often the same: destruction.

Out of the five million E46s you state exist, a very very very VERY tiny percentage of those owners are "car people." an even smaller percentage are enthusiasts. and even if you DO know your E46 information/engine schematics backwards, forwards, up and down, that still doesn't guarantee you're always staring at your gauge and it certainly doesn't guarantee you'll be in a position to pull over and get your car towed. Think about how many situations you could be in where pulling over and/or towing isn't an option. It's better to spend a little now to prevent the headaches of having to tow (often times costing half, the same, or even more than an entire cooling system overhaul).

sometimes its nice to just drive a car with confidence.

the pros of replacing it all greatly outweigh the cons. the only con is you spend $500-720. but really, for a car that costs $7,000-$12,000 used, that's a small price to pay for a responsible working adult to have reliable transportation.

Originally Posted by STiGLiTZ

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

a) you called the water pump plastic -- it's not. Very early ones may have been, but the majority are composite

b) changing over to the Stewart's pump won't magically make the rest of the cooling system more durable - you'll still have to service it at the same intervals. So you may as well stick with OE water pumps and replace them every 75k(ish) miles along with everything else

c) I never cheap out on my car -- but I also dont throw money away. I'm not going to pay 3x extra for a part that gives me very little benefit over the stock part.

Originally Posted by TerraPhantm

a) you called the water pump plastic -- it's not. Very early ones may have been, but the majority are composite

b) changing over to the Stewart's pump won't magically make the rest of the cooling system more durable - you'll still have to service it at the same intervals. So you may as well stick with OE water pumps and replace them every 75k(ish) miles along with everything else

c) I never cheap out on my car -- but I also dont throw money away. I'm not going to pay 3x extra for a part that gives me very little benefit over the stock part.

This.

I think the composite wp impellar is made out of nylon/glass reinforced plastic

sent from my dahc-6900 using Bimmer App

My original water pump failed at under <75,000 miles and around 5.5 years old.

replaced my orginal pump(no issue, just an PM item) at 83k,
now at 126k, my replaced pump shaft leaking coolant.
just merely 40k life of it. however i had my engine overheated(survived) twice with the 3rd party pump.
i've owned this sweetie since 0 mile.

Originally Posted by Alex323Ci

i love when the newbie "know it alls" don't know jack. or in this case.."dude get out your crayons and yellow note pad because this non-rocket science is way above your level of knowledge".

underdrive pulleys like the UUC turn the water pump and the power steering pump SLOWER, not Faster the pulleys are larger and don't turn as much as stock ones..thus "underdriving" them.

now talk more out your pie hole in a rude manner towards members here while we all read it and laugh at how foolish and ignorant to the topic you are.

My sentiments exactly.

Originally Posted by STiGLiTZ

oh and FYI an under pulley kit causes the outer diameter of belt driven wheels to be reduced allowing FASTER spinning so combined with increased flow from the high flow bullet proof water pump i rest my case....not rocket science dude, now if you want to talk about that get out your crayons and yellow note pad so you can take notes

Surely, an underdrive pulley is considered to be an accessory pulley that is LARGER than the stock pulley. (Wiki. Never heard the term personally) In other words, the belt has to travel further in order to turn the pulley through 360 degrees (1 rev). For any given belt linear velocity you would expect fewer revs of the pulley for each belt cycle than with the stock pulley ie: reduced RPM. Since the pump shaft is rigid, not geared, this would result in fewer revs of the vane inside the pump that is responsible for moving the coolant. Reducing flow. Not incresing flow. Yes?

Originally Posted by RayPooley

Surely, an underdrive pulley is considered to be an accessory pulley that is LARGER than the stock pulley. In other words, the belt has to travel further in order to turn the pulley through 360 degrees. For any given belt linear velocity you would expect fewer revs of the pulley for each belt cycle than with the stock belt ie: reduced RPM. Since the pump shaft is rigid, not geared, this would result in fewer revs of the vane inside the pump that is responsible for moving the coolant. Reducing flow. Not incresing flow. Yes?

Haha he's still looking for some crayons he hasn't eaten during nap time and a yellow note pad to take notes. "Dude you're going to fast..underdrive pulleys work how?..der duh".

Originally Posted by E46Mango

the process in which the engine destroys it self isn't the same, sure, but the end result is often the same: destruction.

Out of the five million E46s you state exist, a tiny percentage of those owners are "car people." an even smaller percentage are enthusiasts. and even if you DO know your E46 information, that still doesn't guarantee you're always staring at your gauge and it certainly doesn't guarantee you'll be in a position to pull over and get your car towed. It's better to spend a little now to prevent the headaches of having to tow.
sometimes its nice to just drive a car with confidence.

we have gone over this many times already. agreed, cooling systems don't cause immediate damage to an engine.

a car with new parts is more advantageous than one with old parts, agreed.

do the majority of E46s that experience a component fail in the cooling system have engine destruction..No.
do some that continue to drive with the Red CEL and Red Water Temp Light and Red Battery Light and Red Radiator Light until the engine stops, absolutely.

i absolutely suggest replacing the water pump before it fails and part of a Service Inspection