Frank, is there any way you can put a pressure gage on the cooling system while the engine is running , both at idle and at speed????

When the engine is warmed up, there would have to be a "Lower than atmospheric pressure" condition within the cooling system for it to draw or suck in air from outside the engine. You shold be able to watch fluctuations in the gage as conditions change in the engine, ie, idle vs running speed., warm vs cold, etc.

Good luck on this one. Nice mystery!!

Regards,

John Rodgers 88 GL Driver

Frank Condelli wrote:

>In a message dated 11/17/2003 2:01:14 PM Eastern Standard Time, >LISTSERV@GERRY.VANAGON.COM writes: >Frank, > >Could you tell me in which asylum your "Associates" are quartered? I know >that at times this world sucks and perhaps things are different in Bizarro >World, but I just have to ask them the source of this magical negative >pressure >which is sucking all that air into the coolant system of an idling engine. >Once >they explain that process, I'll be able to contact the Nobel Prize nomination >committee. > Well, my friend George, I am questioning the matter as much as you. >But tell me this, where is the air getting into the system, eh ? I have >pressurised the cooling system to 30# and it held it for over 15 minutes with no >sign of leaking except for three hose clamp connections which I tightened. Then >I pressurised each cylinder to 120# and observed no leaking into the coolant >tank and no loss of pressure for 15 minutes. BUT, when the engine is running >at more than idle there is a fairly steady flow of air bubbles entering the >main reservoir from the upper hose. So where do I go looking for source of this >incoming air ? Maybe you will get the Nobel prize for Wasserboxer leaking >detection ! > > >Cheers > >Frank Condelli >Almonte, Ontario, Canada >BusFusion a VW Camper camping event, Almonte, ON, June 10 ~ 13, 2004 >'87 Westy & Lionel Trains >Member: Vanagon List, LiMBO, IWCCC & CCVWC >Vanagon/Vanagon Westfalia Service in the Ottawa Valley >STEBRO/Vanagon Stainless Steel Mufflers >Frank Condelli & Associates or http://frankcondelli.com > > >