[silvercas]

I have a failed water pump from a 335. Going to trash it in two weeks if no one wants it. You must pay shipping costs (send prepaid label)

[alexwhittemore]

Yep, that was me! I'll PM you.

[mythek]

what can you possibly do with a broken waterpump besides trying to sell it to an innocent victim as a working item? Can you actually open it up and get the working parts out as spares?

[smithf80]

Originally Posted by mythek

what can you possibly do with a broken waterpump besides trying to sell it to an innocent victim as a working item? Can you actually open it up and get the working parts out as spares?

would be interesting to see what actually is broken. and i suppose if you collected enough bad ones that failed in different ways you could make one working one.

[galahad05]

Yup, it was an effort to get failed pumps, disassemble them, and figure out how these guys keep failing--is it the impeller? The motor? The electronics? The housing?

[alexwhittemore]

Originally Posted by mythek

what can you possibly do with a broken waterpump besides trying to sell it to an innocent victim as a working item? Can you actually open it up and get the working parts out as spares?

You can do a failure analysis. I'm an electrical engineer, this type of thing is a fun Saturday project. Rumor has it the failure is electrical, and potentially easy to fix (for someone with all the appropriate equipment on hand, anyway). If that's so, I may be able to save myself some money if and when my own dies. If not, I'll waste no time ordering a new one from the side of the road.

That said, OPs is a 335 pump, not a 328. I suspect they're similar enough to be interesting.

[NightStalker]

let us know how the experiment goes please

[mythek]

Originally Posted by alexwhittemore

You can do a failure analysis. I'm an electrical engineer, this type of thing is a fun Saturday project. Rumor has it the failure is electrical, and potentially easy to fix (for someone with all the appropriate equipment on hand, anyway). If that's so, I may be able to save myself some money if and when my own dies. If not, I'll waste no time ordering a new one from the side of the road.

That said, OPs is a 335 pump, not a 328. I suspect they're similar enough to be interesting.

makes sense, please report back...you may be the first bmw waterpump doctor

[alexwhittemore]

Originally Posted by mythek

makes sense, please report back...you may be the first bmw waterpump doctor

We'll see. One of two things could happen (assuming things are mechanically in-tact): the electronic problem is straightforward and typical of high wear (dead capacitor, failing mechanical structure requiring rework, etc) OR a controller IC has died, which would be effectively impossible to fix without lots of technical documentation or aggressive reverse-engineering of a functional, installed pump.

[Meeni]

There is a core return payment, you may want to investigate this before throwing it away for free. Most pumps can be fixed easily as the failure happens on the electronic board.

[alexwhittemore]

Originally Posted by Meeni

There is a core return payment, you may want to investigate this before throwing it away for free.

elaborate?

Most pumps can be fixed easily as the failure happens on the electronic board.

That's what I'm curious to assess and write up.

[Eddien123]

I always thought it was the fins inside the pump that moved water around that broke off

[alexwhittemore]

Originally Posted by Eddien123

I always thought it was the fins inside the pump that moved water around that broke off

That's one potential failure mode, but I think it's pretty uncommon both for old mechanical pumps as well as new electrical ones. If anecdotes are correct, the first electrical pumps BMW made had longevity issues with impeller vanes, but the vanes aren't the highest stress parts in any pump.

[Len_Beach]

Is this the auxiliary water pump that you're discussing?

I had an error on my original pump so swapped for a second hand part which brought another error.

I was thinking it must be an electrical issue given then differing fault codes.

[simster007]

If anyone is interested, I have a working pump I replaced for ease of mind. 55k miles off my '09 328i. Maybe someone can figure it out if they had both side-by-side.

Would like to sell though...they're expensive

[alexwhittemore]

I'm absolutely interested, and having a known working one would be very useful for comparison to a dead one as well as the 335. But I can't justify working prices for the science project, so I guess if you can't find a buyer, pm me

[alexwhittemore]

Originally Posted by Len_Beach

Is this the auxiliary water pump that you're discussing?

I had an error on my original pump so swapped for a second hand part which brought another error.

I was thinking it must be an electrical issue given then differing fault codes.

There's only one coolant pump, and it'll be the one you replaced. There are lots of reasons it could throw a code for a mechanical malfunction, but I'm not sure it does.