Date: Mon, 19 Apr 2010 10:05:24 -0700
Reply-To: neil n <musomuso@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: neil n <musomuso@GMAIL.COM>
Subject: Re: Over-full overflow tank..cause for alarm?
In-Reply-To: <x2v6bc66ccf1004190918k7c3093cdgf9975743d9419dcf@mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-1
On Mon, Apr 19, 2010 at 9:18 AM, Don Hanson <dhanson928@gmail.com> wrote:
>
>
> Yesterday I did about 250 miles around Mt Hood going to and from a bike
> race and I noticed my temperature gauge was reading slightly lower than
> usual. I put a tank of premium fuel into the van and that is what I was
> burning on this trip, if that would make a difference.
>
> My temp gauge usually reads on or just slightly above the second of the
> bottom two marks...below that LED. Yesterday I was seeing the needle just
> above the bottom of those two lines, even when climbing to ~5000'...until I
> got back to low elevation when I noticed it back nearly to where it always
> has been...Some fluctuations in the reading...Not a fluttering of the
> needle, the gauge looks to be operating normally...but the needle would
> move, over a 10-20min period from quite cool to where it normally has run
> and maybe fall again...So my gauge is showing 'system running very slightly
> cooler than normal'
>
> When I got home I went back and opened the license plate to check my
> coolant overflow tank level. It was over-full and poured out about a cup of
> coolant when I removed the cap...So I opened her up to check the pressure
> tank...No air in there. The coolant looks normal, also..no combustion by
> products are evident. Water pump feels fine, though I didn't take off the
> drive belt and spin it...Next, I went to the air bleed screw in the rad. It
> took about a cup of coolant, added right into the bleed screw hole, as I've
> devised as 'my' method of getting the last air bubble out of my radiator.
>
> So what would cause my coolant to 'migrate' from the pressurized cooling
> system into that overflow tank? and should I be concerned? It's not
> running out of the Normal temp range, but pretty close to 'too cool'... any
> change in operating temp is alarming to me, since when my first problem
> happened, the symptoms were 'cold air from the heater' and the temp gauge
> behaving quite erratically...
I would look at the pressure cap on expansion tank.
My guess is that if it's not holding pressure, coolant will expand
into the reservoir tank. Bentley shows a "Stant" tool for checking the
cap. (I assume your cooling system uses the DV parts)
Search under Mike Elliot's posts. Seems he had the same thing happen.
Subject was "making coolant" or some such.
--
Neil Nicholson '81 VanaJetta 2.0 "Jaco"
http://tubaneil.googlepages.com/
http://groups.google.com/group/vanagons-with-vw-inline-4-cylinder-gas-engines
|