==> More Overheating Fun! With A Leak!!! - United Bimmer Community

**ecks** · 09-17-2007, 10:38 PM

Ok, just so you know, I just replaced my water pump, thermostat w/ housing and drive belt. It was a pretty fun project, except for getting the old water pump out. Well, here is the thing. I bleed the radiator, which even though there are 4 million ways to do it on the net, it took me about 4 times to really figure it out. Now I know I have to do it with the engine completely cool. Anyway, now when I run my car, I have a slight leak in the radiator overflow reservoir right under where I screw in the big rad cap. I really dont think the cap is faulty. It looks like it is leaking right under the black plastic that the cap lies on top of. I'd like to take it off, but that requires a star shaped screwdriver and who the hell has that? Ok, I'm sure you're smart ass does, but I don't! I read one thing online that says that might be a dead radiator. The problem is that when I idle the car, eventually the heat needle goes above 12 o'clock and over heats. I bleed this thing 5 times, but maybe that's it? But why the leak? Thanks!

**xsperf** · 09-17-2007, 10:48 PM

first of all, you know your waterpump is working because you have pressure. Secondly, the reason it is overflowing is because it probably has air in the system. now if you bleed it five times, that means either you didnt do it right, or you have a leak and somehow air keeps coming in. What procedure did you use? As far as i know, there is only one procedure, on the 6cyl it is a plastic screw, engine doesnt have to be hot or cold, just turn it on, heater on too so the coolant circulates through the heater core as well. thats a question, does your heater blow out hot air?

**ecks** · 09-17-2007, 11:02 PM

I have the 4cly. I removed the bleeder screw and then kept filling the reservoir SLOWLY! Then when I filled the reservoir and the bubbles stopped coming out of the bleeder hole and only coolant came out of it I put on and tightened the screw. I took time doing this too. I kept the car off, heat on, but fan off and that's it.

**xsperf** · 09-17-2007, 11:42 PM

you did this with the car off?? how did coolant come out of the hole with the car off?
EDIT: i realize it now, you may have done it after the car still had some pressure in the system. try to do this with the car on, actually, that is the way it is supposed to be done because when the car is off, the waterpump isnt running so the coolant may not be circulating through the entire engine, check out www.pelicanparts.com for a bleeding DIY