[pdxpeter]

Originally Posted by Billfitz

Only BMW knows the purpose of the insulation. I doubt if it has to do with preserving the hoses, as the stock hoses aren't near engine hot spots. I figured it may not be necessary, but it can't hurt, and if it doesn't last the five bucks it would cost me to replace it won't break the bank.

Yeah, put it on if you want. It doesn't hurt. Not going to say you did anything wrong, just that isn't really necessary.

The stock CCV line design has been around for a while so its fairly well known how it works. In the earlier models the lines failed way to early due to heat degradation. The replacements had the insulation to shield them from the heat causing them to fail less often. I can only imagine they continued to use these types of lines because they are cheaper than using full on heater hose. That stuff aint cheap.

[Billfitz]

I did end up switching to SS mesh wrapped hoses, seen in the revised picture a few posts back, because I found the rubber hoses were kinking.