Date: Tue, 20 Sep 2011 21:23:37 -0700
Reply-To: Travis Newhouse <travisnewhouse@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Travis Newhouse <travisnewhouse@GMAIL.COM>
Subject: 85-H20 loss of coolant mystery
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Hi. I just joined the list, and I thought I'd send my first post
about a topic that I'm sure has been covered many times. :)
I have searched the archives and the Web, but I've not yet found
understanding of my problem. I thought I'd seek collective knowledge
of this list.
I have an 1985 Westfalia with gasoline engine. I am having some
issues with loss of coolant that I am trying to understand. I do not
see any noticeable drips or leaks with engine running or not. I
suspect that hot, expanded gas is displacing the coolant. I
appreciate any advice. I have bled the system several times, but
while running, I can see bubbles in the expansion tank.
I can drive at highway speeds (60+ mph) for quite some time - at least
70 miles once. The temperature needle stays right in the middle of
the gauge (over the red warning light). The warning light stays off.
But, when I exit the highway, the temperature starts to rise. While
idling at a signal, or low-speed cruising, the temperature needle will
quickly reach the top of the gauge and the red light starts flashing.
After the light starts blinking and the needle pegs, if I check the
expansion tank before I shut off the engine, I see the coolant level
is 0.5-1.0 cm below the MIN mark. After I shut off the engine, the
coolant level rises up to about the MIN mark. After the engine is
completely cool, the coolant level is about 2-3 cm above the MIN mark.
All the while, the coolant level in the overflow tank is unchanged.
I've tried to bleed the system several times. It seems that after a
bleeding it, when the temp reaches the top of the gauge, then I will
see coolant over-flowing out of the 3 holes on the top of the overflow
tank. So, I suspect that even after bleeding, some gas is entering
the system and causing expansion that forces the coolant out of the
expansion tank and into the overflow tank.
I have seen people describe similar problems while at highway speed,
but I seem to be experiencing the opposite - highway speed is fine,
but idling or low-speed cruising causes the temperature to spike.
I am not sure where to start looking for gas entering the cooling system.
- Is it normal to see bubbling in the expansion tank at idle or while
revving the engine?
- My understanding is that the water pump creates pressure in the
system, and so I don't expect a leaky hose or connection should cause
gas to enter the system while driving (but maybe upon cool down).
Since I'm experiencing air bubbles while running, I'm concerned it
could be exhaust gas, but I'm wondering if there are other sources for
gas to enter?
- What are the easiest to most difficult tests to perform to search
for the source of gas in the system?
Thank you,
Travis Newhouse
Encinitas, CA