Water pump identification

[blee]

Is there a way to determine whether a water pump is the old plastic style or the newer metal style without removing it? Mine is working just fine at the moment, but I can't find anything in my car's incomplete service history to suggest that it was changed at any point.

[shogun]

If you are not sure, change it. You cannot see it from outside. And a new one costs you only 59 $ in the improved version
http://www.autohausaz.com/search/productx.aspx?sid=knm5lq3m1pssyg45nsnu2kmy&makeid=800003@BMW&modelid=1012059@525I&year=1992&cid=16@Cooling%20System&gid=2208@Water%20Pump
Compared to a blown headgasket this is very cheap.
I would also change at the same time the thermostat, and all fluids where you do not have any records when they were changed last time.

[blee]

yeah, a new one is on its way. Maybe I should've thought of this before I made an impulse buy at the shop and had my coolant flushed. Better add a 3-gallon bucket to the shopping list.