OP...could've sworn you had a post on the same thing a couple of days ago. I don't want to bore you with all the details, but first, you can get an ET for under $100 online, but you don't know if that will fix your problem.
You might fix it for a $1 o-ring. It usually is the ET, but that doesn't mean it is.
For now, clean up your car, get it to op temp in your driveway...and find the leak. You can't afford Mango's solution, but you should read his sticky and a few other long 'cooling system' threads...do thread title search (click advanced search).
For you to fix your car and not ruin it, you need to learn enough to be able to diagnose your issue.
A leak is one thing...there might be a reason you had the leak. Have you been driving long enough to see the car overheat more than once? If so, you need to stop doing that. Don't drive the car until you fix the cooling system.
A head gasket is maybe $1000. Head another $500. Block issues...new engine...$3-5,000
Read threads until you want to throw up...actually, until you throw up...you need to feel a chill in your body. A fear. Trepidation. A sense of dread. Then some more throwing up.
Mango's thread is where you begin, but you need to read more. You need to have these symptoms...the chill, dread, puking! Figure maybe 4-5 hours of studying.
Then, go to car and start it, find and fix leak! I know you can do it because it sounds like you have to! Also, there are about 200K of us here...but a good 20 or so who will pitch in and not be too obnoxious!
I can't do too much more in cooling threads anymore as reading them makes 'me' feel cold now...and I'm old...and don't like being cold!
I'll check back...but you can do it. Read, learn, and show your cooling system you know what's up.
Also, remember that when preparing for the repair, the DIY will seem far more difficult than it usually is...and you learn how to put together by taking apart.
Feel the zen of it all...you'll love being done and all good! For now, get to the throwing up part first!
Upcoming NYC dates: Jan 8 and 27. See Facebook for other shows and PM me if you can make one...love to see you there!
Mangofy your E46!
Last edited by dmax; 10-05-2012 at 06:39 PM.