I've done a bit of searching around here and didn't find the answers so I'll apologize in advance if I'm posting about a well known issue. First post as well. I picked up a well maintained 2007 R56 S model with turbo about a year ago. It's at around 93,000 miles now. It's had an extremely small mystery coolant "leak" for a few months. Just a little puddle under the left front. Definitely coolant and not A/C condensation. I have searched in vain for any source. Recovery tank looked like it had a little wetness around the seam so I replaced that last week. The small puddle persists same as before. I also noticed that the recovery tank will fill to the absolute top after a drive, possibly even forcing a little coolant out of the cap (maybe the source of my "leak"??) I've never gotten and overheat warning or any obvious signs of overheating. I did bleed the system after replacing the recovery tank, even though I didn't drain the coolant at all to do the swap. I'm just curious as to what might be going on. Sorry for the long first post here, but any replies would be greatly appreciated.

Gar

 

https://www.northamericanmotoring.co...rchid=16574023

 

...for me.

 

Link doesn't work for me either.

If you can't find a source for the leak --- like a wet spot on the block, or a loose / leaking hose or coupling, you might have a bigger problem. Coolant coming out the top of the tank could be from a blocked hose, bad pump, or cylinder compression getting into the coolant jacket. You should consider removing some of the air intake plumbing to get access to coolant hoses, then get up close and personal with them, to find a wet spot.

When I blew my engine, compression got into the coolant jacket and forced a couple hoses off the thermostat housing. That was a BIG coolant leak. A smaller compression leak will have less pressure, but still cause coolant to be forced out someplace. A compression or leak-down test might help if nothing else is obvious.

Common leaks sources I've experienced are thermostat housing gasket, recovery tank swivel joint hose connection, and 0-rings on pipe between pump and thermostat housing. Also read about the oil filter housing gaskets failing (there's coolant in there too).