528i Touring cooling system possible fault

[B10 v8]

After replacing viscous FAN, THEROMSTAT housing, bleed screw and expansion cap, the cooling system seems to be fine, the coolant was below the KALT_COLD Level and the car run fine. I topped up the coolant to just below the highest COLD level or a little below. Then afetr running the car idle for about 15 mins, I noticed water dribbling out from under the front undercarriage. When I checked the coolant level this moring the level is back to where it first was. This doesn't seem normal to me, is it?

Do some cooling systems like to run with less coolant than others :confused

Any thoughts?

[xpcgamer]

When I did my overhaul I caught my self tighting the cap too much and it would leak from there. Also If I over fill the expansion tank it always settles itself to its proper level. I guess it will bleed the overage I guess.

[B10 v8]

I understand what you are saying. The thing is I didnt over fill the exp tank. I filled it to a little below the coolant line. This is why I'm puzzled. When the car is totaly cold and I check the coolant level its seems to be 4" below the correct level. But as I say the car doesn't run hot, just normal :confused. Also the temp gauge does work as when I first turn the car over the car runs on the cold temp until a mile or so driving then the temp needle reads halfway on the gauge.

Any thoughts?

[easyover]

I personally wouldn't be comfortable with this until I knew where the water was coming from. Get it up on ramps, pull the belly pan and trace the leak.

[B10 v8]

Should also add while running the car idle for the 15 mins I had the A/C running. So the water leaking from under the car could have been from the A/C. But why then has the coolant level become low again at the level it was before I topped it up:confused

Drove home yesturday from work 7 mile trip with no A/C running when home. I checked the coolant level and is at the same level as the previous morning. Totaly :confused now

any thoughts?

[B10 v8]

Any ideas?

[legitsnowe39]

At least ur not leaking coolant.of the coolant level is maintained I wouldn't worry about that.but if ur engine temp starts to creep the tiniest bit stop the car and get it towed. I had slight leaking, and a little overheating, took it in found out the leak was in the headgasket. I suggest finding the leak, and always watch that temp gauge!

[B10 v8]

It turns out it was the Expansion bottle had a leak in the bottom of the bottle. Hopefully all is well again!:D