No.  It's not normal to have air getting into the system as you describe.

There are a couple of ways it can happen.  One is that there is a slight
leak so that when the system cools it sucks air in instead of coolant
from the overflow tank.  The other, of course, is combustion gases
getting into the coolant from a leaky head gasket or a cracked head.

I change my coolant every 2 years and don't have the problem you
describe between changes.

I once did have the problem but in my case, ('84 Wasserboxer), the head
was cracked badly enough between the valves in #2 that combustion gases
were entering the coolant.  No problems since I replaced that head.

Mike
'84 GL 7 pass
'84 GL Westy
'85 GL Westy

Don Hanson wrote:
>   Is air getting into the cooling system a common, recurring problem with Vanagons?