The short answer is the wrong thermostat was in there. It was the 80 degree thermostat instead of the more popular and correct for most installations: the 87 degree unit.

I share this for those who don't know. Seems the opening temp is stamped on the thermostat. I had gotten the cooler thermostat from Lithia VW in Reno when I was travelling. The part number on the box was for the correct 87 degree thermostat but the actual thermostat has a number like 212 80 stamped on it. I asked the parts guy at the time and he said "No that's just a code number. You go by the part number on the box." So I installed the thermostat and completely forgot about the conversation.

The bus had been running hot prior to the thermostat install and so I was thrilled when it was running cooler--especially in the desert. As time passed and I did more driving I noticed the temp gauge was usually pretty low except in traffic. Since I had installed a new temp guage sensor as well I thought it might be faulty--or coolant was passing by the thermostat or what have you.

At any rate I opened the system and the second I saw the 80 stamp and it all came flooding back to me like from a busted radiator hose.

I suppose for many this is a no brainer, but I figured I'd pass it on.

Rennie at Peyton Cramer VW in Torrance set me up with the correct thermostat and some other hoses and stuff for this most recent fix. Rennie is a hero if you own a Vanagon and I highly recommend you deal with him.

Best
Jeff
83.5 Westy
LA,CA