BMW: water pump pully ect.., timing belt tensioner, harmonic balancer

Question
I have a 1989 325i and my waterpump pully has spun, (no more 4 holes now just 1 big hole) just wandering if you have came across this before? the pump seems fine but i am going to replace it anyway.So does all the front covers have to come off? I cant seem to see the inboard most bolt. any suggestions would be appreciated. Thanks

Answer
Tim,

 I'm not sure how you would have spun the pulley, unless the waterpump locked up for some reason, I would definately replace the pump.
 
 My water pump went out about a week ago on my 87' 325i, so I did this recently.

 If you are changing the water pump, I would HIGHLY recommend replacing the timing belt and tensioner.  You only have to remove a few more bolts to get to it, so it's well worth the time spent.  

 First, you should remove the hood so you can work on the car, its only 6 bolts, and pretty simple to do.  If you dont, you'll be cursing all day!  Next you need to remove the fan that (used to) attach to the water pump pulley, and remove the radiator.  Remove the distributor cap and rotor button, and now you can start removing the covers from the engine.  The top cover that the distributor rotor sits in is held on by 3 bolts, one on each side, and by one at the bottom.  The one at the bottom is slotted, so all you need to do is loosen the nut and the cover will slide off.  Now you should remove the Harmonic Balancer 6 - 13mm bolts hold it on.  Hold the crank by the large bolt going through the center of the harmonic balancer, and remove all 6 bolts.  Once they are  removed, the pulley will slide off.  Once the pulley is off, grab the larger pulley that has "teeth" on it, and pull it off.  
 Now you can remove the lower cover, which should only have 2-3 bolts holding it on.  Thats IT...

 From here on, make sure you DO NOT turn the crankshaft or camshaft, because you will be removing the timing belt, and it will get one or the other out of time.  Next, remove the timing belt tensioner.  It's a roller that is right beside the water pump, that keeps the T-belt tight.  Once removed, you can slide the timing belt off and discard it.  Now remove the water pump.  There are 3 bolts in a triangle pattern (you should have a new pump, so you can look at it.).  
 Replace the waterpump with the new one, and then put the NEW tensioner on.  There is a spring on the tensioner, and you will have to compress the tensioner ALL THE WAY before you can get the new T-belt into place.  Make sure its in time as well!
 Reassemble everything as you took it apart, and you should be fine!

 Hope this helps,
 Josh