Slow drip underneath - E85 (M54)

[griff325]

Hi (I am a newbie to this site!!)

My E85 2.5i (M54) has a slow drip (once everyone 10 seconds) or so when parked on a slight gradient. The coolant level had been low with the light coming on when I started the car but going off after driving 500m or so.

I topped it up with genuine BMW coolant (50% water & 50% coolant) and nothing has dripped through when parked in the garage. The temperature gauge has never moved off the central position so it doesn't seem to be overheating in anyway.

The water is coming from the aircon drain but I have not been using the aircon as I haven't driven it for a week. I just took it out of the garage to check my tyre pressure and that is when I noticed it. The water looks clear but has left a light stain on the drive. Any ideas? The radiator looks fine....

I live in Australia and although garaged, the nights are down to 5C and daytime temps only 20C at the moment so I doubt it is humidity related. Could it be a collection of rain water??!

I have owned the car for 10 years and not experienced this except when the aircon is on all the time in temps over 30C. Is there anything else that could leak out of the aircon drain?

Thanks in advance

[mjennings23]

Is there any smell or colour to the liquid? If it is just water then it'll just be the drain for the air con.

I assume it's coming from near the gearbox?

[Bing]

My car drips water from the aircon drain pretty much all the time. It doesn’t take long to start, even at relatively low temperatures.

[RickRob]

Are you sure it's not a "mechanic" from a Halfords Autocentre?

[ph001]

The coolant expansion bottle are notorious for this. Probably a pinhole in it. Need to remove to inspect properly.