Dumping coolant??

[Cadeez]

Hey guys, I need a little guidance here... I just did a little cooling system refresh on my '01 330i; I replaced the thermostat, upper rad hose, exp tank and coolant level sensor. When I was done I bled the air from the system by filling the exp tank until the coolant started coming out of the bleeder screw in the upper rad hose. I ran it until it was hot, with the defrost on high, until the thermostat and heater core opened up, then let it cool completely and topped off the exp tank. Checked for any leaks, all looked to be dry & perfect. Which as far as I'm aware, is the correct process...right?

So now, not quite every time, but about every other time I drive my car, long or short distances, when I come back out to it there's a big puddle of coolant underneath it. If I refill it, the process perpetuates, if I don't, the coolant light comes on the dash. I can look down under the exp tank and see where the coolant has dripped/poured onto the plastic bottom cover. I am beside myself, seriously frustrated and pissed, it makes no sense whatsoever. Thoughts??

[ryankokesh]

I would guess something isn't connected quite right, and then when it gets hot it expands and leaks.

Also, I think you're supposed to bleed until you stop seeing air bubbles in the coolant that's pouring out the bleeder screw. As opposed to just when you first start to see coolant come out. You do that with the car in Accessory, and the heat on "Hi".

[Cadeez]

Okay, I'll have to get back under it this weekend and make sure everything is connected firmly, the exp tank was a bitch to get off & on. You'd think it would leak at all times though if that was the case, I know all the clips are secured in the grooves, not sure what else there would be. Good point on the bleed process too, I'll make sure to do it that way this time. This is my first time messing with the cooling system (obviously), I'm slightly out of my comfort zone. Thanks for the advice!

[ryankokesh]

No problem. These cooling systems are a bit finicky. But, it's giving you lots of experience already :) At this rate you'll be a pro in no time!

[imola red zhp]

It lay also be the Exp tank could be leaking, and has happened to me that the connection to exp. tank was cracked at the bottom.
Good luck

[ELCID86]

Try pulling up on the expansion tank. If it pulls up it wasn't seated properly. (You may want a bucket under it). Do the same for all the other hoses.


Thumbs, iPhone, Tapatalk.

[Cadeez]

Try pulling up on the expansion tank. If it pulls up it wasn't seated properly. (You may want a bucket under it). Do the same for all the other hoses.


Thumbs, iPhone, Tapatalk.

Yeah I'll try that, I figured I'd start pulling and jiggling stuff before I took anything completely off, thanks!

[danewilson77]

Need update.

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