plastic impeller on water pump?

[kris]

my 740 needs a water pump but the one i ordered fro napa came with a plastic impeller.Do all the 7's water pumps have plastic impeller's or metal? i want to make sure i get the proper one as i don't want to change it again for a while.

[marti5]

The pump should have a metal impeller, I did mine 6 months ago and got one from BM and one from a motor factor store, the store was plastic & BM was metal, original one is metal, I have heard horror stories of these plastic ones being fitted and lasting around 10,000 miles or less.

There is no way I would fit one with plastic, but its up to you.

[MMSTech]

I assume this is an E38 740. Go to the dealer and get this pump. It may be a few dollars more but you can rest assured the part is of good quality and fits properly. I also like to replace the two o-rings that are on back of the pump to the pipes. Also if it has over 80,000 miles on it. Now would be a good time to replace the thermostat. Its easy job but much easier to replace during installation of the water pump.

[Teh Prof]

Now, all that being said...your water pump problems won't be over.

I replaced my plastic impeller pump on my M3 with the metal impeller one; 37000 miles later, the bearings failed, breaking the serpentine belt, which destroyed the radiator and assorted hoses...