Tuesday, June 12, 2012 - 12:28 pm, by: Mike Beck(Gold_40gt)
I was part way through doing my water pump / cam belt replacement and thought I would share the differences in water pumps between revisions.
The new OEM pump on the right its about 5 revisions newer than the used one from 1992, so has been redesigned accordingly through the years.
It seems the impeller is of a different type of plastic too... almost metallic like and has more blades.. (better flow I imagine?)
Interestingly the drive wheel has gone from a hard plastic type to stainless steel or alloy!
The current pump had only recently started to fail with water leaking through to the bearing and the odd few drips coming out the outlet to indicate this. Pretty remarkable how good the impeller was though, even after 20 years. I think few other manufactures could do the same... original BMW coolant impellers are notorious for breaking!