E90 335 Series Water Pump Pictures

I think many of us are facing water pump replacement of have done so already. I thought it would be a good idea to post pictures of the most current water pump for the 335 made by Continental. VDO also makes them but I don't have pictures of that one and assume form fit function is the same. The picture on the right shows the Continental logo...
This is what sits in a padded box with the aluminum TTY bolts in my trunk...

Originally Posted by fun2drive

I think many of us are facing water pump replacement of have done so already. I thought it would be a good idea to post pictures of the most current water pump for the 335 made by Continental. VDO also makes them but I don't have pictures of that one and assume form fit function is the same. The picture on the right shows the Continental logo...
This is what sits in a padded box with the aluminum TTY bolts in my trunk...

You may well find that all of the water pumps are not only similar, they are exactly the same because they were all made at the same factory. It's common.
I don't have any experience yet with the 335 pumps, can you get both new and rebuilt? About 20 years ago the price of new pumps became very competitive with rebuilts and I completely stopped using rebuilts. Nothing specific against a rebuilt, but in this application I'd very strongly recommend a new unit.

Interesting side note: While my car was in the dealership for a metric-butt-ton of stuff (recall I had a whole lot of front suspension parts replaced because of a piece of hard ice + the valve cleaning etc.) I asked my SA about whether it looked like my water pump was going. His response: No, they didn't see any leaks or weeping.

What are your thoughts on this, DSX/anyone? Are the vast majority of water pump failures evidenced by leaks before they go?

Originally Posted by galahad05

Interesting side note: While my car was in the dealership for a metric-butt-ton of stuff (recall I had a whole lot of front suspension parts replaced because of a piece of hard ice + the valve cleaning etc.) I asked my SA about whether it looked like my water pump was going. His response: No, they didn't see any leaks or weeping.

What are your thoughts on this, DSX/anyone? Are the vast majority of water pump failures evidenced by leaks before they go?

Our fancy *ss electric pumps rarely leak externally because of their construction. Note that in fun's pics there is no shaft coming out of the pump to drive an engine accessory belt. All the action is contained inside the pump, no seal is required around a shaft which leads from the inside to the outside. That's the beauty of an electric pump.
But there's a dark side. They're electric pumps. Take a look at the closest lightbulb. When is it going to suddenly stop working? Right, same with the pump. And it probably won't be in your driveway on a lazy Saturday morning. There is a seal internally between the wet parts like the impeller, and the dry parts, like the electric motor. Eventually they leak. And electric motors don't like coolant baths. That's why Mike Miller and others suggest a preemptive strike; change it before you are majorly stuck somewhere.
The question becomes when? That depends on your risk tolerance. I'm unsure of Mike's suggestion, with normal driving I think they'd go 90K miles, but maybe 1% will go before that. Probably won't be yours, but like the lottery, someone's ticket eventually gets called.
Lottery gambler
Coolant pump gambler

I would think CPO covers water pump failure so most of the pumps would last more than 100k miles (my is at 139k miles). There must be other external factors (way it's driven, temperature) that causes a higher failure rate in some cars.
You read about people's early failures and other people do early replacement so you never know if they will last more than 100k miles.

Originally Posted by fb88

I would think CPO covers water pump failure so most of the pumps would last more than 100k miles (my is at 139k miles). There must be other external factors (way it's driven, temperature) that causes a higher failure rate in some cars.
You read about people's early failures and other people do early replacement so you never know if they will last more than 100k miles.

That's right. Some are even going to last over 200,000 miles if it's a bell shaped failure distribution and the 60,000 mile failures are in the minus 3 sigma area.

Water pumps are mission critical components, and the consequence of failure can be high both in time and money. If a headlamp goes out you have another one, if an ignition coil fails you run on five until you get home, if a tire loses pressure you have run flats or a spare (right?). If your water pump fails you stop soon, either because you had enough sense to, or because your engine refused to go any further. Now what? Are you on the Cross Bronx Expressway at 2 a.m.? The Five in San Diego at 8 a.m. or I-70 near East Nowhere, Kansas in the middle of a blizzard? Your call.

Many 'Fest members keep their cars up, they do scheduled maintenance and want their cars to be reliable. They can afford a BMW, they can afford maintenance -even when parts haven't failed yet. Others...well, everyone has their own life to lead and responsible adults can make their own decisions and then accept what comes.

The same can be said of the mechanical water pumps too which failed many times without warning or with some warning coolant coming out the weap hole.
I do think BMW will continue to improve their electric water pumps to the point reliability will be well north of 100K miles but as has been the case with the HPFPs users tend to be the field testers.
Thus the reason a new pump is in my trunk and I will replace this at 70K miles and keep the old pump. When my E93 hits 140K miles it will get a new pump again as well as a new automatic transmission pan and other typical long life maintenance.

I wish we knew more about the failures of the current pumps and how they are rebuilt. My guess is that both VDO and Continental rebuild pumps that have failed. I have seen two types of failure, electrical short to ground which might well be because of water instrusion and cracked phenolic casing which is where you see visible coolant. What I don't know is if the other failures are seal failures or not.

I hope anyone that has experience with water pump failure meaning you saw the pump or your tech could tell us what you saw or were told. I think we need to build our database (nonscientific as it might be) on these pump failures.

I know this isn't well recieved but an electric pump is a good idea compared to a mechanical pump for more precise control...

DSXM ---

Great explanation on the electric coolant pump! I am nervous about mine failing soon. E91 2007 w 116K miles.

I've had low coolant warnings twice in the past year. First time I only had to fill less than a quart. the second time, seems like half a gallon.

I looked down the engine bay and noticed that there's wet (likely coolant) spots at the bottom panel/tray. This is almost directly under the headlights towards the very bottom of the car. Something is leaking. Could it be the water pump? Or just hoses/connections? I need to open the panel up and inspect.


I have not yet had high temp warnings. I'm very nervous because my daily commute is ~ 45 miles (1.5 hrs) each way on LA freeways.

I guess I should preempt and change the pump/t-stat soon. But in the meantime, what about the leak? Any guesses?

Thanks!

Originally Posted by DSXMachina

Our fancy *ss electric pumps rarely leak externally because of their construction. Note that in fun's pics there is no shaft coming out of the pump to drive an engine accessory belt. All the action is contained inside the pump, no seal is required around a shaft which leads from the inside to the outside. That's the beauty of an electric pump.
But there's a dark side. They're electric pumps. Take a look at the closest lightbulb. When is it going to suddenly stop working? Right, same with the pump. And it probably won't be in your driveway on a lazy Saturday morning. There is a seal internally between the wet parts like the impeller, and the dry parts, like the electric motor. Eventually they leak. And electric motors don't like coolant baths. That's why Mike Miller and others suggest a preemptive strike; change it before you are majorly stuck somewhere.
The question becomes when? That depends on your risk tolerance. I'm unsure of Mike's suggestion, with normal driving I think they'd go 90K miles, but maybe 1% will go before that. Probably won't be yours, but like the lottery, someone's ticket eventually gets called.
Lottery gambler
Coolant pump gambler

The only way you can tell is to pull the pan and look. Something is leaking and it could well be your pump dripping down the hoses. If mine was leaking at all something is wrong.
If this was my car I would be doing that and planning to replace it if you see anything coming from the pump...

Out of my past 5 BMW's in the last 6 years, 3 of them needed the electric water pump replaced, two with the thermostat. Two of those had the pump fail with no warning, away from home needing a tow. All three were less than 60k miles before failure.