I was plagued with overheating problems all summer, and finally had to take my car off of the road due to a water leak. The leak became progressively worse as time went on and eventually I was adding coolant daily. Realizing that I could slack no more on my beloved '79 323i (with an '88 325i block), I decided that I need to fix the cooling system. My thermostat works fine. The hoses are fine. The radiator is sealed. So, since the above is true and the water seemed to be leaking from the area around the water pump on the front of the block, I concluded that it is indeed a problem with my water pump. So, I just checked the archive and saw that there is an old posting about some heating system leak that can develop in e21 320's.

http://forums.roadfly.com/e21/messages/archive/msgsy2000w14/2299.html

Is a similar problem possible with my 325i block (is there a steel tube with a hose connecting the cooling system to the heating system as in a 320 that could be causing a leak?), or should I just proceed with the usual water pump replacement? Basically, I just want to know that it IS my water pump that is borked before I replace it, and the problem on the 320 is the only other cause I can think of. So, how can I be sure that my water pump is bad?

By the way, while my cooling system is dismantled, I am replacing the radiator as well . . . FINALLY!

Thanks in advance . . . any insight is appreciated!

Brian