water pump R&R

[allsierra123]

Any idea how to get at the bolts behind the IP seems awfully tight in there. Trying to just remove the WP and alternator and leave all else in tact.

[92EcoDiesel Jetta]

Any idea how to get at the bolts behind the IP seems awfully tight in there. Trying to just remove the WP and alternator and leave all else in tact.

Have you figured out how to remove the water pump?

[92EcoDiesel Jetta]

installed a new water pump cast iron, on a new AAZ motor.  Motor ran about 10 degrees warme. Tried everything to determine why, from new temp sensor, new voltage stablizer in cluster, etc.  5 years later it started to see and installed a stamped steel one, as that was what was available.  10 degrees cooler.  Big difference. One of other fellow also swapped to a stamped impeller and noticed the same.

The stamped ones actually cool better.

That's very interesting and contrary to every other report I've heard.  Looking at the actual fit of the blades to housing I can't see how the stamped one could flow better but I'd definitely be interested in seeing a flow test.  I have a used cast impeller pump I'd donate, but no stamped version here. 

I have since spoken to 2 local VW mechanics and they both said they never had problems with the stamped metal impeller pumps running hotter. Just looking at the stamped metal compared to the cast plastic impeller (that's currently in my) car, the stamped one looks like it has more surface area than the cast. Maybe the stamped ones does move more water and cool better? I guess the only way to find out is to do an actual flow test on each type. Since I've got my hot running issue resolved (stuck thermostat), I am not motivated enough to run such a test anymore. If anyone else does run the test, please be sure to tell us about it.