2000 e39 bmw 528i found metal filings in Antifreeze when flushing aft water pump fail

[riverjamie]

After finding water pump leaking. I decided to flush coolant system. When draining radiator (5 yrs old) I found some metal filings. Not sure if aluminum or steel? Didn't think to try magnet on them. So I did a flush until I saw no more filings. The Radiator is a Behr model with aluminum fins and plastic sides. Any thoughts? thx

[E39 Newbie]

Did the failed water pump have a plastic or metal impeller?

[riverjamie]

The old water pump had a steel impeller and looks like its intact. I didn't notice before I removed the old water pump if it was maybe rubbing on the inside of the housing? I wish I would've done a magnet test on the filings. I'm hoping that it's just some filings from the radiator? I don't really see it coming from anything else? Any other thoughts?

thanks

Did the failed water pump have a plastic or metal impeller?

[Chedley]

How old is the radiator ? and the water pump ?? I'd guess those metal shavings are coming from the water-pump steel impeller.

[riverjamie]

Water pump I think is 9 years and the radiator is 10. There have been on signs of leakage until the water pump starting leaking the other day. They both have about 47K on them.

How old is the radiator ? and the water pump ?? I'd guess those metal shavings are coming from the water-pump steel impeller.

[Perern]

I've heard that the metal impeller can hit the engine if the bearing is starting to go bad. Check if there are marks of it rubbing.

[jclausen]

The metal impeller could dig into cylinder #1 bore if the water pump bearing was loose and caused it to wiggle a lot when you remove the pump you can see the bore right there, hence the plastic impeller, people say plastic impeller is stupid well there's your reason why they use it

[riverjamie]

It doesn't seem that there's any play in the Water pump shaft. But who knows at high speed. I wish I new about the plastic impeller, I would have ordered it instead of metal one that's coming today? Oh well only planing on keeping car another two years. Thanks again for all the feedback.

The metal impeller could dig into cylinder #1 bore if the water pump bearing was loose and caused it to wiggle a lot when you remove the pump you can see the bore right there, hence the plastic impeller, people say plastic impeller is stupid well there's your reason why they use it

[E39 Newbie]

There are two schools of thought on the plastic impeller. My BMW mechanic friend prefers the metal ones, saying they last longer. You'll find the subject debated on various boards.

From my somewhat limited experience, 10 years is way past time to replace both items. It's not just the mileage, it's the age.

[mattmar1]

just an fyi, the impellers were plastic on the early E39's, which had a failure problem. the plastic was done away with, impellers are now composite and more reliable. ive been using HEPU water pumps with stainless impeller for quite a while now with no issues. HEPU is the OEM for volvo.

[wagons ho]

Did someone previously load up the system with stop leak?
It is silver metallic, and looks like metal.

[riverjamie]

no stop leak

Did someone previously load up the system with stop leak?
It is silver metallic, and looks like metal.

[jicaino]

I use Hepu pumps too, and cut a thicker silicone gasket on the V8 to prevent chances of the impeller rubbing. On the I6 haven't replaced it yet, leaning towards HEPU too.

[crazy4trains]

Who cares what the stuff is. Time for a total cooling system refresh or this e39 will be in the boneyard soon.

[riverjamie]

All together again. Hopefully holds together for a few more years.

Thanks for all the feedback

Who cares what the stuff is. Time for a total cooling system refresh or this e39 will be in the boneyard soon.