Date:         Fri, 10 May 2013 17:19:52 -0700
Reply-To:     Gary Peebles <captn.peebs@VERIZON.NET>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Gary Peebles <captn.peebs@VERIZON.NET>
Subject:      possible gasses in coolant system?
Content-Type: text/plain; charset="Windows-1252"

This is a follow up on the 88 van, Paco, that was heating up more than usual.  I had previously had slow water leaks and kept the system full of tap water while in South America (16 months). I repaired those leaks and then drove to Alaska last Summer.  In Calgary I blew a head gasket.  Found a good mechanic who worked on it.  I did not cook the engine, the head was in good shape, he put it back together.  I drove another 6,000 mile.   Before a recent trip to Death Valley, I had the radiator replaced, it was seriously clogged.  I drove it in almost 100 degree temps and it ran a little hot but never a red light, just second fan level.  I blew another hose, in Tonopah, Nevada,  one that was replaced this last summer.  I believe it was because of an in proper placement of the hose clamp on the top side of the lip to the distribution tube.  Got that repaired and drove home 600 miles.  got great gas mileage and the van never got heated up more than the first fan speed.  At first the expansion tank had no air in it at all.  After the repaired hose and the fill up of the coolant system in Tonopah.   When I got home the expansion tank was half full of air????  

Dennis suggested that I tighten the head bolts, do a leak down test of both the heads and the coolant system.  I just did have those things done. All bolts torqued down nicely, and were not loose.   Each chamber held the pressure it was supposed to and the coolant pressure never got above 12psi.  

The right head, that had new gaskets put on it last summer compression tested to 120 each, the left side is 150 and 165 psi.  I did find out that the engine, which is a GoWesty 2.2 L has a slightly different cylinder to head gasket than the 2.1 L .  The inside diameter of the 2.2 is 2mm larger than the 2.1.  The outside diameter and the thickness of those metal gaskets are the same.  GoWesty puts a copper gasket in, I  think we had the aluminum replacements for a 2.1 L put in.  Would that cause such a difference in compression from one side to the other.  My mechanic and I are at a loss as to the difference.  

The engine has good power and seems to be right on with the temp when running.  So should there be any air in that expansion tank at all ever in a normal operating engine?  I guess our next step is to drive it for a while, and see what happens...If I get more air in the expansion tank after a lone drive what should I assume????   Next step is ??  Jerk the heads and see what's going on?  engine has 70,000 mile on it, it doesn’t eat abnormal amounts of oil.  
Thanks again for any suggestions.  
Gary