[nycbr]

2008 328xi [N51]
56k
auto
no problems with water pump [or anything else]

[d8rknight]

Died at 79k all stock

[Artmasterx]

Originally Posted by Mr.Ritz

How much is the part and labor to replace water pump?

Originally Posted by SoGood

How much is a WP if it fails. at like a indy shop to fix?

Generally speaking based on previous replies (for WP + thermostat):

Parts: $500-600
Parts+install at indy shop: ~$1200
Parts+install at dealer: ~$1500 (+?)

Please correct me if I am far off.

[bender rodriguez]

Do they make aftermarket water pumps for these cars?

[PINeely]

Originally Posted by Artmasterx

Generally speaking based on previous replies (for WP + thermostat):

Parts: $500-600
Parts+install at indy shop: ~$1200
Parts+install at dealer: ~$1500 (+?)

Please correct me if I am far off.

That's about what you'll be quoted. It's a really straightforward fix though, no reason to pay a shop IMO, or at least not a reason to pay for more than 2 hours labor. OEM Pumps can be had new for just over 400 dollars.

Originally Posted by Mr.Ritz

Do they make aftermarket water pumps for these cars?

Aftermarket pumps are available but they cost almost the same as the genuine part. Go OEM.

[GoRomeo]

Originally Posted by PINeely

That's about what you'll be quoted. It's a really straightforward fix though, no reason to pay a shop IMO, or at least not a reason to pay for more than 2 hours labor. OEM Pumps can be had new for just over 400 dollars.

Thanks for the info but seems like NOT having the car lifted on a shop it makes it more dificult to work on stands doesn it? I am just thinking out loud how if if I attempt to do this job.

[bender rodriguez]

Originally Posted by PINeely

That's about what you'll be quoted. It's a really straightforward fix though, no reason to pay a shop IMO, or at least not a reason to pay for more than 2 hours labor. OEM Pumps can be had new for just over 400 dollars.

Aftermarket pumps are available but they cost almost the same as the genuine part. Go OEM.

Why it seems OEM fails in this case.

[PINeely]

Originally Posted by GoRomeo

Thanks for the info but seems like NOT having the car lifted on a shop it makes it more dificult to work on stands doesn it? I am just thinking out loud how if if I attempt to do this job.

If the car was lifted it would certainly be easier than the job is on your back, but the pump is really easy to get to. I'm a mechanic and it takes me about an hour to do one from start to finish but that's flat on my back. The pump is on the front passenger corner of the engine, bottom of the car. Lift it up and it's there as soon as you crawl under the car.

The most time consuming part of the job is taking all of the clamps and hoses off of the thermostat. That's where having the car on a lift would really pay off since you'd have more room to pull and tug.

Originally Posted by Mr.Ritz

Why it seems OEM fails in this case.

As far as parts which are readily available go, OEM is the cheapest option. If you want to source up a non-OEM pump when you finally find one that's less than OEM it will be 10 dollars cheaper and you'll be ordering it from some no-name website that nobody has ever heard of. Additionally there are no data on aftermarket pump failures so they could very well be worse on it than OEM. An alternative would be to order a pump directly from VDO since I think that they make the OEM pumps, but again, you are talking 395 versus 400 dollars and ordering from a mystery party.

PS: BMW has never been known for their cooling systems so any pump that you put in there will probably fail eventually. The fact that this model's pump is so expensive is just a stroke of bad luck for us.

[GoRomeo]

Originally Posted by PINeely

If the car was lifted it would certainly be easier than the job is on your back, but the pump is really easy to get to. I'm a mechanic and it takes me about an hour to do one from start to finish but that's flat on my back. The pump is on the front passenger corner of the engine, bottom of the car. Lift it up and it's there as soon as you crawl under the car.

The most time consuming part of the job is taking all of the clamps and hoses off of the thermostat. That's where having the car on a lift would really pay off since you'd have more room to pull and tug.

As far as parts which are readily available go, OEM is the cheapest option. If you want to source up a non-OEM pump when you finally find one that's less than OEM it will be 10 dollars cheaper and you'll be ordering it from some no-name website that nobody has ever heard of. Additionally there are no data on aftermarket pump failures so they could very well be worse on it than OEM.

PS: BMW has never been known for their cooling systems. The fact that this model's pump is so expensive is just a stroke of bad luck for us.

Cool thanks for the info. I am glad we have a mechanic in the house and thanks for your advice. Really not looking foward to this job anytime soon but I am starting to do my research on this just in case.

[woodpecka]

Originally Posted by PINeely

If the car was lifted it would certainly be easier than the job is on your back, but the pump is really easy to get to. I'm a mechanic and it takes me about an hour to do one from start to finish but that's flat on my back. The pump is on the front passenger corner of the engine, bottom of the car. Lift it up and it's there as soon as you crawl under the car.

The most time consuming part of the job is taking all of the clamps and hoses off of the thermostat. That's where having the car on a lift would really pay off since you'd have more room to pull and tug.

As far as parts which are readily available go, OEM is the cheapest option. If you want to source up a non-OEM pump when you finally find one that's less than OEM it will be 10 dollars cheaper and you'll be ordering it from some no-name website that nobody has ever heard of. Additionally there are no data on aftermarket pump failures so they could very well be worse on it than OEM. An alternative would be to order a pump directly from VDO since I think that they make the OEM pumps, but again, you are talking 395 versus 400 dollars and ordering from a mystery party.

PS: BMW has never been known for their cooling systems so any pump that you put in there will probably fail eventually. The fact that this model's pump is so expensive is just a stroke of bad luck for us.

Is it much easier if you don't change the thermostat?

Have you done it on an XI?

There are some oem pumps for 320$ shipped on ebay.

[GoRomeo]

Originally Posted by woodpecka

Is it much easier if you don't change the thermostat?

Have you done it on an XI?

There are some oem pumps for 320$ shipped on ebay.

I believe you have to remove the thermostat in order to get the water pump. Someone can confirm this. I think some water pumps are a bit cheaper than others, depending on what kind of engine you have.

[PINeely]

The thermostat is connected to the water pump with two bolts. There are three further bolts connecting the water pump to the crankcase. In theory you could leave the thermostat connected to the car after you remove those bolts and the thermostat -> water pump hose but you'd have less room to squeeze the pump out, maybe not enough. It's easiest to remove both parts at once I would think.

The sway bar needs to be lowered to access the pump as well. Four bolts, takes seconds.

I haven't changed one on an XI but it should be the same procedure and parts. Pumps are the same across the line with the exception of the M3 and 335d, which both use belt-driven pumps rather than electric.

[Artmasterx]

Originally Posted by PINeely

The thermostat is connected to the water pump with two bolts. There are three further bolts connecting the water pump to the crankcase. In theory you could leave the thermostat connected to the car after you remove those bolts and the thermostat -> water pump hose but you'd have less room to squeeze the pump out, maybe not enough. It's easiest to remove both parts at once I would think.

The sway bar needs to be lowered to access the pump as well. Four bolts, takes seconds.

I haven't changed one on an XI but it should be the same procedure and parts. Pumps are the same across the line with the exception of the M3 and 335d, which both use belt-driven pumps rather than electric.

Good to know, thanks!

[ExpensiveTaste]

Originally Posted by PINeely

The thermostat is connected to the water pump with two bolts. There are three further bolts connecting the water pump to the crankcase. In theory you could leave the thermostat connected to the car after you remove those bolts and the thermostat -> water pump hose but you'd have less room to squeeze the pump out, maybe not enough. It's easiest to remove both parts at once I would think.

The sway bar needs to be lowered to access the pump as well. Four bolts, takes seconds.

I haven't changed one on an XI but it should be the same procedure and parts. Pumps are the same across the line with the exception of the M3 and 335d, which both use belt-driven pumps rather than electric.

The only difference with the xi is that the subframe covers alot more of the area that would be used for reaching in to. Taking off the passenger wheel and using long extensions to take off the hoseclamps was easiest.

[mym32fast]

Pretty sure died today. Haven't officially got it diagnosed but pretty sure it's the water pump. quote from a friend at the dealership quoted me $1401. My car is a 2008 335xi w/ 68xxx miles

[Artmasterx]

Everyone, I have compiled initial statistics based on 183 responses so far.

Everyone help out by voting!

I switched to a binomial-based distribution which is better for proportions (always exists between 0 and 1):


Plot of estimated failure rate during specific mileage intervals:


Plot of estimated failure rate before a specific mileage (perhaps more interesting to some of us):

(I didn't really propagate the uncertainty correctly, so the uncertainty is probably larger at higher mileages)

Looks like there may be a lot of failures between 60-75,000 miles, and a relative lull in failures between 75-100k miles (though still uncertain). This could mean that some pumps fail early and other batches are more robust. However, it could also be a function of the heterogeneous sample of turbo/non-turbo cars, different driving styles, etc...

Still, predicting a 50% chance of failure before 75,000 miles kind of sucks! (and ~65% before 100,000 miles)

Interesting nonetheless!

[Patel511]

Died at 52k

[woodpecka]

Originally Posted by Artmasterx

Everyone, I have compiled initial statistics based on 183 responses so far.

Everyone help out by voting!

I switched to a binomial-based distribution which is better for proportions (always exists between 0 and 1):


Plot of estimated failure rate during specific mileage intervals:


Plot of estimated failure rate before a specific mileage (perhaps more interesting to some of us):

(I didn't really propagate the uncertainty correctly, so the uncertainty is probably larger at higher mileages)

Looks like there may be a lot of failures between 60-75,000 miles, and a relative lull in failures between 75-100k miles (though still uncertain). This could mean that some pumps fail early and other batches are more robust. However, it could also be a function of the heterogeneous sample of turbo/non-turbo cars, different driving styles, etc...

Still, predicting a 50% chance of failure before 75,000 miles kind of sucks! (and ~65% before 100,000 miles)

Interesting nonetheless!

Word!

[Efthreeoh]

Not to throw cold water on this whole statistics lesson, but I think the better data to make a statistical analysis from is time (rather than mileage) and type of use (i.e. percent split between city and hwy driving). The water pump fails due to the heat load it sees based on the environment it operates in. A water pump in car that sees more stop and go driving in Dallas, Texas will fail at a different mileage than a water pump in a car that sees no heavy traffic in Anchorage, Alaska. Tying failure rates to mileage, while you can make a statistical evaluation, is not a true measurement of predictability when a pump will fail as a result of mileage.

Also, throwing in N52s into the data set is going to skew the results because the water pumps for each engine are different parts. You should not be trying to correlate failure rates for two different models of water pumps.

Considering the high cost of replacement, it would be a disservice to members of this Forum to have them use this thread to decide when a preemptive replacement of the water pump should be made (i.e at 70,000 miles). Being that the cost for replacement is anywhere between $800 - $1,200 (non-DIY), it is probably better for an owner to wait until the pump fails and have roadside assistance insurance to handle the tow bill. A much better investment would be for an owner to buy a BMW-reading scan tool and periodically scan the car for the shadow codes that indicate the pump is starting to fail. Having been through this whole ordeal, this is just my opinion.

[Artmasterx]

Originally Posted by Efthreeoh

Not to throw cold water on this whole statistics lesson, but I think the better data to make a statistical analysis from is time (rather than mileage) and type of use (i.e. percent split between city and hwy driving). The water pump fails due to the heat load it sees based on the environment it operates in. A water pump in car that sees more stop and go driving in Dallas, Texas will fail at a different mileage than a water pump in a car that sees no heavy traffic in Anchorage, Alaska. Tying failure rates to mileage, while you can make a statistical evaluation, is not a true measurement of predictability when a pump will fail as a result of mileage.

Also, throwing in N52s into the data set is going to skew the results because the water pumps for each engine are different parts. You should not be trying to correlate failure rates for two different models of water pumps.

Considering the high cost of replacement, it would be a disservice to members of this Forum to have them use this thread to decide when a preemptive replacement of the water pump should be made (i.e at 70,000 miles). Being that the cost for replacement is anywhere between $800 - $1,200 (non-DIY), it is probably better for an owner to wait until the pump fails and have roadside assistance insurance to handle the tow bill. A much better investment would be for an owner to buy a BMW-reading scan tool and periodically scan the car for the shadow codes that indicate the pump is starting to fail. Having been through this whole ordeal, this is just my opinion.

Certainly a valid point (The time metric is much harder to define), and I didn't intend for this to spur preemptive replacement. But it is good to understand when that it actually represents a reasonably high probability of failure. I added your quote to the OP...

[Efthreeoh]

Originally Posted by Artmasterx

Certainly a valid point (The time metric is much harder to define), and I didn't intend for this to spur preemptive replacement. But it is good to understand when that it actually represents a reasonably high probability of failure. I added your quote to the OP...

Thanks for the effort to run the equations; it's a good first start.

I think time is actually easy to define. All BMWs have an "in-service" date, which the customer who bought new knows (it's the day he picked up his new car), bought-used owners can find out from BMW. Most people also know what type of traffic they usually encounter. It's another set of data that would help determine statistical failure rates.

[PINeely]

Originally Posted by Efthreeoh

Not to throw cold water on this whole statistics lesson, but I think the better data to make a statistical analysis from is time (rather than mileage) and type of use (i.e. percent split between city and hwy driving). The water pump fails due to the heat load it sees based on the environment it operates in. A water pump in car that sees more stop and go driving in Dallas, Texas will fail at a different mileage than a water pump in a car that sees no heavy traffic in Anchorage, Alaska. Tying failure rates to mileage, while you can make a statistical evaluation, is not a true measurement of predictability when a pump will fail as a result of mileage.

Also, throwing in N52s into the data set is going to skew the results because the water pumps for each engine are different parts. You should not be trying to correlate failure rates for two different models of water pumps.

Considering the high cost of replacement, it would be a disservice to members of this Forum to have them use this thread to decide when a preemptive replacement of the water pump should be made (i.e at 70,000 miles). Being that the cost for replacement is anywhere between $800 - $1,200 (non-DIY), it is probably better for an owner to wait until the pump fails and have roadside assistance insurance to handle the tow bill. A much better investment would be for an owner to buy a BMW-reading scan tool and periodically scan the car for the shadow codes that indicate the pump is starting to fail. Having been through this whole ordeal, this is just my opinion.

N54 water pumps and N52 water pumps are identical. They're the same in the N55, 335iS and 1M as well. Only the M3 and 335d pumps are different in the 3 series.

How do you suggest calculating the number of hours run by each pump? As you said in a heat-sink situation mileage isn't the best data point but it is the only usable one really. From there you could split it into highway mileage or city mileage to account for the load times, but... too may people in here with cars they bought used and not knowing whether it was highway or city driven. Too many people who've had their cars since new and have driven a good mix of highway and city. Too many whose cars are FBO and are run harder, hotter, longer than a stock car. Too many people who let their cars idle for 30 minutes every morning under which circumstance lots of heat-sink and no mileage occurs.

Mileage is the only data point which is going to be standard across all of the pumps. Amount of heat sink is going to be different for every single car.