M50/S50 Water Pump and Thermostat Replacement

["Ron Buchalski" <rbuchals@xxxxxxxxxxx>]

I'm in the process of replacing the cooling system components in my E34 (M50 
engine), and I had a few questions.  The car has 154k miles on it, and I've 
driven 101k of the total.  I've never replaced the water pump, and I don't 
believe that the previous owner did.

Q1) There is no mention of using any type of a sealer between the thermostat 
cover and the engine block.  So, the thermostat gasket and the second rubber 
gasket under the cover are all that's needed?  No sealants (Permatex) is 
used?  The Bentley manual doesn't say anything about it, but I didn't want 
to assume that no mention means nothing required.

The water pump has a metal impeller.  The impeller is silver, sort of a 
spot-welded piece with eight blades.  The replacement pump (from BMP) is a 
Graf pump.  It also has a metal impeller, but it's one of those cast pieces, 
it's black in color, and it only has seven blades.

Q2) I'm concerned about putting in a pump with fewer blades on the impeller. 
  The factory pump looks (to me) like it'll be a better pump.  Has anyone 
installed a Graf pump?  Any problems?

Thanks!

Ron Buchalski
BMWCCA #76387
1995 E36 M3
1993 E34 525iT
1999 Mazda Miata




_________________________________________________________________
Choose an Internet access plan right for you -- try MSN! 
http://resourcecenter.msn.com/access/plans/default.asp

------------------------------