[Thecouper]

Hey all!

So my 328i is almost 70k miles.
I know that the water pump will fail.
I got 1k quotes for several shops around here, so Im thinking in doing the change myself in a few month. (380 usd the kit on FCP)
My questions is: If the water pump suddenly fails, what could go wrong?
Do I burn the engine for not being cooled or the car will auto turn off and I'll be able to wait for the tow truck?

Im afraid that I can toast the engine just for being cheap and not wanting to pay 1000bucks for a water pump !!!

Thanks!!!

[E92_William]

I would wait, I waited till 160k miles when the thermostat got stuck open but the pump still worked. You’ll get a warning before anything actually gets too hot if it fails. I wouldn’t spend 1k on it just because.

[EwenMac]

As a new by I worried the same, at 17 years old and 224,000 km has the pump been already changed?. I don’t know. So what I did was I have an elm327 obd tool and an old android phone running torque lite (free) and I can monitor my coolant temp on the run, so having done that in a variety of conditions, and comparing coolant temp and oil temp I feel relatively confident , time till tell

Hope that helps

[Efthreeoh]

Failing N52 pumps were early model E90s. BMW redesigned the pump a few times since 2009. Mine failed in 2011 at 149K. The upgraded pump has lasted 13 years and 276,000 miles so far and has never thrown a code.

My '08 Z4 has never yet thrown a code and it's at 121,000 miles.

Just scan the ECU periodically. Usually you'll get time to replace the pump once you get the slow-speed code. The slow speed condition doesn't overheat the engine. Also, the ECU protects the engine if it starts to over heat. Worst you wait and can drive it home once it cools down, or pay for a tow.

[Grease23]

It depends on what you use the car for.

If you don't drive it stupidly when it tells you it is overheating, you shouldn't fry your head gasket or engine. It could fail gradually with some warning or all at once.

I just replaced my working 11 year old pump at 70,000 miles. Why? Because I drive long trips and go through remote areas where a breakdown would be a real PITA. So for peace of mind, I did it. If I were just driving it around town or from urban area to urban area, I'd have let it go longer.

Go with an OEM pump if you do it. It is doable on a garage floor but not a fun repair if you have big hands. There are good DIY instructions on here.

[crashoverride]

I actually drove on a failing pump about five miles. The car goes into limp mode so doesn’t go very fast (I was on freeway and it was like 45-55 mph) apparently limp mode I’m told will pump air through the cylinders to cool engine. Not smart, not proud I’ve since put 150k miles so no long term problems.

[jsunma]

Mine lasted (2008 MY) about 140K miles, and even then I only replaced it since I was also getting the oil pan replaced (rusted through) and I figured that it might as well get done since access was quite easy at that time. In other words, it didn't exactly "fail". The replacement has chugged along just fine for 100K since then and will get replaced when it actually does fail.

There was a time though, when the N52 engines were new(ish) that these forums were full of people who were convinced that if they didn't replace their water pumps every 50K miles their engines would grenade. ("My car has 60,000 miles on it. Is it ok if I take it on a 200 mile road trip??") That all pretty much turned out to be hysteria (except for early E90s as Efthreeoh notes). So, don't be looking at those old posts. Read your codes. Don't drive the car if the temp light is lit...and carry on.

[StradaRedlands]

Anecdotes incoming: My early '06 lasted to 140k. The '09 started throwing thermostat codes at 124k and I changed it then with the tstat, although it may have been fine? Our '11 F10 (N52 motor) had it misdiagnosed and changed at 120k. So from my experiences, 70k is waaaaay too early and 120k is very possible.

It is an easy job when you do decide to do it. Just take it slow and be methodical.

[lowrydr310]

Originally Posted by Grease23

I just replaced my working 11 year old pump at 70,000 miles. Why? Because I drive long trips and go through remote areas where a breakdown would be a real PITA. So for peace of mind, I did it. If I were just driving it around town or from urban area to urban area, I'd have let it go longer.

This is smart, but 70K seems early. I'd have pushed it to 100K.

My old 325i water pump failed, not mechanically but an electronic fault that took out the BSD bus. No codes, just INACTIVE on the oil level display. I followed the TIS diagnostics using ISTA which traced to the water pump.

I have no idea when my 335i water pump was last replaced. I bought the car last year and while I have a bunch of service records, there's nothing about the water pump. Last time I replaced the radiator and hoses, I noticed when bleeding that the pump was making a funny grinding sound at low speed. I keep looking for codes but none yet and the pump is still working fine, but that is the one thing on my mind that would make me think twice about going on a long road trip in this car.

[krhodes1]

I've always said I will change mine at 100K. But at the current rate I put miles on my 328!, that will be in roughly 2055.

Don't worry about it, just drive the thing.

[whyzee125]

I wouldn't preventatively replace a water pump on these cars, the failures are too random to be able to predict. I'm N54, but I've had one pump crap out with less than 1k miles, one at 25k, another last about 100k and many others on this forum have over 200k. If yours is working, leave it alone.

The car won't turn off as that would be a safety issue. It will warn you at which point you'll have enough time to pull over safely and wait for a tow.

[ctuna]

Do you drive long distances where and on the Road Repair would cost you a lot ??
If you get a red temp light stop driving right away.

[Cpet]

Originally Posted by ctuna

Do you drive long distances where and on the Road Repair would cost you a lot ??
If you get a red temp light stop driving right away.

Agreed. Depends on your usage of the car and your risk tolerance. My cooling system is original at 83K and I haven't had any warning signs of failure yet. I'll likely do a whole overhaul at 100k to be safe, but if the hoses still seem soft then, I may push back the timeline.

[lookalikehuuh]

Another anecdote incoming: My 06 330i had a waterpump overspeed code at like 120K miles. I cleared it and it apparently worked great for years after that. At around 170K miles I figured I had pushed my luck long enough and I replaced the thermostat and WP at the same time. It never failed. Its replacement has also not failed and car sits at 230K miles now.

[Bims328i]

Get a scanner in the meantime and keep an eye out for speed deviation codes. More than likely you will have a small window to repair it. It is not difficult to replace too.

[DBShiznit]

One thing I've learned is that you shouldn't wait for it to fail as it could fail at the most inopportune time. Plan to do it and have the peace of mind that it is done. It's not like you'll have to worry about doing it any time soon after. And if you're doing it yourself it'll be cheaper like you said. Just take your time. I did it in a couple hours and that was socializing with a buddy while doing it. Also if you're doing it yourself and saving yourself the money do a couple of while you're in there hoses. That also helps and don't forget about the MM flange on the head. Also much easier to do once you already have the coolant drained. You could probably be under $450 for everything.

[Efthreeoh]

Originally Posted by DBShiznit

One thing I've learned is that you shouldn't wait for it to fail as it could fail at the most inopportune time. Plan to do it and have the peace of mind that it is done. It's not like you'll have to worry about doing it any time soon after. And if you're doing it yourself it'll be cheaper like you said. Just take your time. I did it in a couple hours and that was socializing with a buddy while doing it. Also if you're doing it yourself and saving yourself the money do a couple of while you're in there hoses. That also helps and don't forget about the MM flange on the head. Also much easier to do once you already have the coolant drained. You could probably be under $450 for everything.

You could follow that protocol for nearly every component on the car and go broke maintaining it.

[DBShiznit]

Originally Posted by Efthreeoh

You could follow that protocol for nearly every component on the car and go broke maintaining it.

That’s why everyone should look at maintenance of these vehicles when purchasing. That was something I took into consideration myself. Preventive maintenance is key to keep these cars running well. Why wait for failure of components we know the vehicle will need at some point soon given the age and possibly the miles? I could get in either of my N54 vehicles and go across country with full confidence it won’t have an issue, unless it’s something I couldn’t prevent. There’s always something that will be out of our control.

[Efthreeoh]

Originally Posted by DBShiznit

That’s why everyone should look at maintenance of these vehicles when purchasing. That was something I took into consideration myself. Preventive maintenance is key to keep these cars running well. Why wait for failure of components we know the vehicle will need at some point soon given the age and possibly the miles? I could get in either of my N54 vehicles and go across country with full confidence it won’t have an issue, unless it’s something I couldn’t prevent. There’s always something that will be out of our control.

I'm the original owner of my 2006 E90 325i. It passed over 425,000 miles in July of this year. I used to drive it 85 miles to my office one way, 5 days a week for 8 years straight, then 3 days a week up until the end of 2021. The E90 has never been over-maintained. I've pretty much followed BMWs CBS schedule.

IMO most owners here on E90 Post believe the internet hype and way over-maintain these cars. The early N52 waterpumps fail because of overheating control electronics. The pump was redesigned to vastly reduce the failure rate. My opinion is the waterpump failure is overblown on the internet. And replacing the t-stat/WP combo is stupid if neither component fails. The metal-bodied t-stats failed, the brown phenolic t-stats don't fail. If the t-stat does fail, (a) it can be replaced without removing the WP, and (b) it fails open and does not disable the car. But the internet hyped it all up and lots of owners needlessly replace both components at 100,000 miles because the internet says so. The parts are $500 all by themselves. If the N52 WP fails, most times you can let the engine cool off and drive it home.

One can play the guessing game and try to replace components that are meant for lifetime service proactively and spend thousands of unnecessary dollars doing so and make the car no more reliable than it already is. It's my 2 cents, but I have over 1M ownership miles with the BMW 3-series for the past 38 years to fall back on.

[Grease23]

The "poll" available on this website certainly influenced me in my conclusion that I ought to do it at 70,000 miles.

[DBShiznit]

Originally Posted by Efthreeoh

I'm the original owner of my 2006 E90 325i. It passed over 425,000 miles in July of this year. I used to drive it 85 miles to my office one way, 5 days a week for 8 years straight, then 3 days a week up until the end of 2021. The E90 has never been over-maintained. I've pretty much followed BMWs CBS schedule.

IMO most owners here on E90 Post believe the internet hype and way over-maintain these cars. The early N52 waterpumps fail because of overheating control electronics. The pump was redesigned to vastly reduce the failure rate. My opinion is the waterpump failure is overblown on the internet. And replacing the t-stat/WP combo is stupid if neither component fails. The metal-bodied t-stats failed, the brown phenolic t-stats don't fail. If the t-stat does fail, (a) it can be replaced without removing the WP, and (b) it fails open and does not disable the car. But the internet hyped it all up and lots of owners needlessly replace both components at 100,000 miles because the internet says so. The parts are $500 all by themselves. If the N52 WP fails, most times you can let the engine cool off and drive it home.

One can play the guessing game and try to replace components that are meant for lifetime service proactively and spend thousands of unnecessary dollars doing so and make the car no more reliable than it already is. It's my 2 cents, but I have over 1M ownership miles with the BMW 3-series for the past 38 years to fall back on.

I’m not saying rebuild the motor. I’m talking about components that are known to fail. Both my n54s had the water pump fail, reason why I said I spoke from experience. It also depends on where you live and how much the temps fluctuate. I’ve had many BMWs myself so our experiences could be different. These e series cars weren’t around for 38 years and e36s also had cooling issues. I never had an issues with the e30s I owned. Most of it was all metal back in the day anyway.

[fastboatster]

I'm going to say whether you need to do it preventatively depends on a few things.
#1 are you taking any long road trips or just doing local commute
#2 whether you got n51/n52 vs n54/n55 engines.
#3 current mileage
I'll say that for local commute, especially if you have n51/n52 engines then you can wait. Going to be a long wait, though, my lci pump did 130kmiles and then I just replaced it, but it was fine.
other end of the spectrum is an n54/n55 car with some miles and you decide you want to take it on the road trip. Yes, then replace the WP.