Date: Wed, 7 Feb 2007 13:36:57 EST
Reply-To: Oxroad@AOL.COM
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Jeff Oxroad <Oxroad@AOL.COM>
Subject: Re: Need input on radiator problem
Content-Type: text/plain; charset="US-ASCII"
Hey Jim--
Yes, the fan and the sender were working fine on both slow speed and high
speed in my case.
I mention the high speed fan coming on because that was noticeable from the
cockpit. My ears basically don't hear the fan on slow speed unless I'm actually
out of the bus doing a test.
BUT I did check all that at the time and the fan came on for both speeds.
If I recall correctly the radiator has an upper and lower chamber of cooling
tubes. Hot coolant runs through the top half of the radiator then through the
bottom half. The fan switch in the bottom half.
So like Ben's client with the Mexicali blues I would say my fan came on
"late." But I'm not sure it really came on all that late in the scheme of things.
It was more of the case that I would get off the highway, stop at a traffic
light watch the temp gauge go up, up, up. I would open the interior heater. THEN
the fan would come on high speed.
And while this all took place in probably a matter of less than a minute,
when the high speed fan "finally" came it was after I had watched the gauge go up
and after I turned on the heater and so I might be inclined to say to the
bus, "Oh NOW you come on?"
But the truth is it came on in a fashion that was not the problem.
I would guess a couple of things accounted for this.
1. With a properly working radiator that fan on high speed brings the coolant
temp down pretty quickly. With the compromised radiator what chance does the
high speed fan have? All the air in the world moving around the coolant
passages isn't going to help when the inside of those passages are "insulated" by
mineral deposits. Also the coolant movement would theoretically be slower
through a compromised radiator.
2. On that slower coolant movement: the engine temp went up each time I
stopped at the traffic light after being on the highway. The hotter coolant was
pumped to the radiator's top chamber and moved slowly (with in reason) through
the radiator and that hotter coolant, certainly hot enough to get the fan sensor
to bring the fan to the higher speed, didn't reach the fan switch "right
away". So there was a delay I'd say, all-be it relatively slight, in the high
speed fan coming on. Then like I said it seemed a little late. But the truth is
the radiator was the problem.
I had a theory that the fan switch might also be compromised as the part that
sits in the coolant might be insulated by deposits. But when I took the fan
switch out it was clean and worked fine.
My original radiator was copper and it served well for say 16 or 17 years. It
would sound like your radiator is 23 years old. It certainly might be due for
a replacement.
FWIW I used the correct VW coolant of course and distilled water. I figure to
some extent with the distilled water I'm avoiding mineral deposits down the
road. I'm guessing the previous owners used tap water with minerals and thus
mineral deposits sattled in over the years.
I hope some of that helps.
Thanks,
Jeff
83.5 Westy
LA, CA
In a message dated 2/7/2007 7:56:59 AM Pacific Standard Time,
jkurpius04@SBCGLOBAL.NET writes:
Jeff,
My 84 westy behaves similarly to what you described. Did you test
that both radiator fan speeds were working properly? You mentioned
the high speed would come on, but nothing about the low speed.
Jim
84 westy
SF CA
