Could be the early signs of combustion gasses getting into the cooling system. Loose or cracked heads.

Dennis

Sent from my Windows 10 phone

From: Michael McSwain<mailto:michaelmcswain@GMAIL.COM>
Sent: Wednesday, February 17, 2016 12:40 PM
To: vanagon@GERRY.VANAGON.COM<mailto:vanagon@GERRY.VANAGON.COM>
Subject: Expansion tank under pressure when cold?

My temp gauge is sporadically running a little high and I smell a faint
sweet smell of coolant so I'm trying to track down the leak(s). So during
all of this I tried to top off my coolant and noticed something unusual, or
at least I think it's unusual. So when I look at my expansion tank coolant
level is just above the upper hose inlet. Last time I did any maintenance
to my coolant system I think I remember being able to open the expansion
tank when the van was cold and add coolant if needed.  I also remember
being able to open the expansion tank with the engine running at around
2.5k rpms.  Now no matter what the conditions are, every time I try to open
the expansion tank the level quickly rises and the tank begins to overflow.
Is that normal? Does that mean that I have too much coolant in the system
or could it mean that there is a blockage or restriction somewhere?
--
m.