Similar problem for me with my 1.9 engine. 

        Happened for me under extended load.  

        Same symptoms with Expansion and over flow tank.  Repeated bleeding when it first happened didn’t help.

Now being assessed for repair or more.

I wish us both good luck!

Eric Caron 
85 GL Auto 
 
> On Oct 29, 2017, at 2:36 PM, Shirewood <doug@SHIREWOOD.COM> wrote:
> 
> I was afraid you were going to say that. Thanks. It's seemed like the expansion and overflow tanks haven't been operating correctly. I've replaced the expansion tank, cap and hose to overflow. After it warms up there will be air in the expansion tank and lots of coolant in the overflow.     ?
> 
> Sent from my iPad
> 
>> On Oct 29, 2017, at 10:40 AM, Dennis Haynes <d23haynes57@hotmail.com> wrote:
>> 
>> Loose or cracked heads!
>> 
>> Dennis
>> 
>> 
>> -----Original Message-----
>> From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of Shirewood
>> Sent: Sunday, October 29, 2017 11:28 AM
>> To: vanagon@GERRY.VANAGON.COM
>> Subject: Cooling system '85 1.9
>> 
>> This has been very frustrating.  Started with serious overheating. Replaced thermostat with great effort (broken bolts). I have been adding coolant, burping air, over and over but when I test drive as soon as I hit a hill it overheats.  Any suggestions? Thanks Doug E.
>> 
>> Sent from my iPad