High Temperature Coolant Reservoir Failure

[Eric]

What evidence can you see @DenisM? Is it losing pressure also?

I wiped off what I believe was white cyano adhesive powder residue from both my reservoirs maybe six months ago and it hasn't returned. I've seen similar pics posted with that same white residue so assumed it's a leftover from manufacturing.

I have had that white residue on both reservoir seams for the last 14000 miles, with no issues, I thought it was common on BMWs!

 

[bakepl]

Have same white ring around my tanks, certainly not as bad as image in previous post here but strong smell of coolant under bonnet after driving. Mentioned it to the agent here and they'll take a look when handles are replacing in a few weeks.

 

[CRH]

If you have the white leak marks, they need replacing, and will under warranty, your HVAC will improve