M50 Water Pump

[Steve N]

Hopefully some has an answer before I finish this project. My old water pump with the plastic impeller grenaded itself yesterday. Should I be concerned with the parts being in the cooling system? That is a lot of plastic. Where did it go? I want to button everything back up tonight so hopefully some has a quick answer.

-Steve

I added a pic of the new and old.

[billb]

Hopefully some has an answer before I finish this project. My old water pump with the plastic impeller grenaded itself yesterday. Should I be concerned with the parts being in the cooling system? That is a lot of plastic. Where did it go? I want to button everything back up tonight so hopefully some has a quick answer.

-Steve

It's still going strong now in 2005 at 127k miles. I have since replaced the water pump again, and replaced the radiator and all hoses in 2001 at 80k miles. As long as you flush out the system as best you can, including backflushing the radiator (take it out, turn it upside down, and flush through it that way), that's about all you can do.

[danzee]

I had the same thing happen two years ago. I found all the parts except for a piece about 3/4" square. I was worried it might clog some part of the cooling system. Brett said not to worry, it would probably end up in the bottom of an engine cooling passage without doing any harm. I noticed no ill effects on engine cooling after finally getting all the air bled out.
However I did lose my aux pump shortly thereafter. The failure mode was the bonded joint of the magnetic coupling breaking loose from the impeller. It's not unreasonable that an obstruction like the missing water pump piece could have stressed the aux pump enough to make the joint break. The passages are a bit narrow in the aux pump.
YMMV
Z