newbie rad prob

[beemer bum]

i am the new proud owner of a 1999 bmw 323i. i won't wax poetic about the ride, suffice it to say, i'll never leave the marque.

now, i've just had a horrifying occurence. i got a light for the rad on the dash. heat was okay. when i turned off, i noticed fluid leaking onto the pavement. opening the hood some very hot high pressured spraying was still taking place and a fair amount had been forced out from the looks of the hood and surrounding parts. it wasn't drenched, just wetter than i would have liked. the rad cap or at least where the fluid was coming out of (i'm new to beemer technological wizardry) seemed to be sound, seals and all looked fine, it was fitted tight).

questions: what would have caused this hissing out of fluid? i just recently had it serviced (level one) at the local bmw dealer, and it inlcuded a flush. i've put a couple of thousand kilometers on it since with no perceivable problems.

2. am i filling up the rad right? i added some water to the spout (this is the area which seems to have a hydrometer rod which floats upwards at the addition of fluid). i've heard others commenting on "bleeding" the system. i have not seen an overflow jar. i would assume that, once i find it, should be maintained at a proper level as well. can anyone educate my relative stupidity with my new toy?

much thanks.

[Jeron]

The top radiator neck is prone to cracking so the leak could be from there but it could be a cut hose or a loose hose or any of several areas. If you have BMW brand coolant you can look for the white powdery residue it leaves when it dries to help find the leak.

There are several discussions that include proper bleed technique.
Here's one:
Overheating - Strange

The rad cap with the float is the expansion tank.

Your 99 323i is an E46.