Weird coolant leak...

[Sockethead]

Nope, not at all. Usually it's over tightened so bear that in mind when you replace it. It has an O-ring so it doesn't need to be super tight.

[danewilson77]

Have we discussed the brass replacement option yet?

S7 Edge, out

[Sockethead]

Negative...

[ZacharyMikel]

Oooh! I had a coolant leak that looked exactly like yours. Crusty around the top of the expansion tank, and lots of drips all over the place. I replaced everything in the cooling system except my upper radiator hose. Guess what? The plastic fitting on my upper rad hose was a piece of crap, and was letting coolant slowly drip out over the top of the expansion tank.

I remember worrying about it daily, every time I drove it. Constantly turning my center display to show temperature, etc. while I was trying to eliminate the issue. While it would be SWEET if your problem was just the bleeder screw, I would assume that with that much around the ET, it's gonna be either the tank or the upper radiator hose.

[ecrabb]

Have we discussed the brass replacement option yet?

We didn't, but I saw the discussion on E46F. I kind of had to agree with the poster who said the risk of the brass plug is that it's much harder than the plastic it goes into, and that the plastic plug is safer by design.

SC

[ecrabb]

So, follow up... It's fixed. I think it was indeed the bleeder screw.

I took it out and cleaned it up, and couldn't see anything wrong with it. I screwed it back in and it broke off in the receptacle. Arggghhhh...



So I used a technique I saw on E46F, heated a regular screwdriver with flame, and melted a slot to screw it out...



Picked up a new one at the dealer, put it in, bled the system, and I think I'm all squared away.

Cars and coffee in the morning!

Thanks, guys!!!

SC

[ecrabb]

Btw, after comparing new and old, I think it was a combination of a deformed (flat) o-ring, and then the screw itself was failing structurally and developed a pinhole from the top of the threads to the big recess in the center.

SC