I have a 1988 735i. It has been leaking coolant from somewhere by the water pump but I couldn't see it. Yesterday the upper radiator hose split. I replaced it and when I was filling the coolant (without the car running) it started leaking again by the water pump. I took the hose off the water pump and the leak was still there, but only when I was filling the resivour. Question is if the water pump was leaking wouldn't it only happen when the car was running? When I poured water directly into the water pump it didn't leak, only when filling through the resivour, but it basically poured out around the area under the water pump. Also, right side headlight doesn't work, fuse is good, any ideas? Thanks. I just want to get ideas before I replace the water pump as it looks pretty new. Also does anyone know where I can find details on water pump replacement online? Thanks again!

As for a DIY article on the water pump, there's one at e38.org/e32. It's for a 750, but relatively the same process, starting on page 16 of the provided pdf.

The water pump can leak whether the car is running or not. If it's an 88, and the previous owner never mentioned replacing it, it is probably time to do so anyway. You may have a leak coming from the thermostat house on the water pump...?

I looked at the pdf on e32 but that is for a V12 5.0. I think the 3.5 l6 must be an easier fix as it doesn't look at though I need to remove the harmonic balancer. Thanks for the reply though as I didn't know if the water pump could leak without the car running or not.

Does anyone know if the radiator needs to be removed?

link from my website
http://evansweb.info/articles/2003/01/18/water-pump-replacement

headlight problem
http://www.bimmerboard.com/forums/posts/255204/

I am sure that will help. Thanks again. Do you know how long it takes?

I am sure that will help. Thanks again. Do you know how long it takes?

That all depends how experienced you are. But take your time and don't hurry.
Resoldering of the LKM is done in less than 1 hour, if you have done it before.
Or bring it to an electronic repair shop, if you have no experience with soldering electronics.
On my website below there is a good instruction on how to solder electronics, what soldering iron to use etc.

Thanks for the info! I got the water pump off in about 20 minutes! Hopefully putting it back on will be as easy! The pump was $47.98 US at Advance Auto Parts. On a scale of 1-10 taking it off was about a 3.

Yeah, on the 735's it should be pretty straight forward. At least you do not have the extra pipes that go from the w/p to the rear of the motor under the intake manifold like the v8 motors, because it's a pain in the arse if you accidentally pull them out from the back side...