Date: Mon, 19 Apr 2010 22:52:09 -0700
Reply-To: Scott Daniel - Turbovans <scottdaniel@TURBOVANS.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Scott Daniel - Turbovans <scottdaniel@TURBOVANS.COM>
Subject: Re: Over-full overflow tank..cause for alarm?
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I think you're on the right track Don - get a quality fresh t-stat in there,
consider if the pressure cap and it's little flow-back valve are working ...
and the hose from pressure bottle to overflow/license plate bottle.
any time I see the temp fluctuating ....
and it's not anything to do with air or exhaust in the coolant, then I think
t-stat.
also running warmly enough is super important.
If you have been running at say only 30 % of the temp gauge ...probably been
running too cool all along.
'mostly' the temp gauges are pretty reliable and accurate.
I find 'usually' 180F at the engine shows right about 50 % of the temp
gauge....right on the LED.
easily verified with an infra red temp gun.
Sometimes I find minor variations in temp senders...
not sure what you engine uses, but the typical one that's single contact
with push-on wire connector is what I'm thinking you might have. ...
( found on 1.9 wbxr's, diesels, and syncro vanagons - for the gauge )
.......If I try 5 different used ones on one van...
they can vary some ...some will read a needle's width low, some that much
high, etc. Just check that the engine is running close to 180 F...and that
needle on gague is at mid-deflection at that temp.
I suspect you have an ok reading gauge and need a good new t-stat, and a
fully intact 'no-leaks' cooling system.
any time I am thinking about gauges ...like maybe they are weird, I consider
the Voltage Stabilizer ..
a little gizmo on the back of the instrument cluster .....small back thing
secured with one screw.
The test is in Bentley ...affects gauges ...................just saying to
at least remember that part is there and is related to gauge function.
I find a bad one every once in a great while.
have fun !
Scott
www.turbovans.com
----- Original Message -----
From: "Don Hanson" <dhanson928@GMAIL.COM>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Monday, April 19, 2010 9:58 PM
Subject: Re: Over-full overflow tank..cause for alarm?
> That is way beyond my meager electrical ability..running a diagnostic
> like
> that. Though I am getting some base knowledge, having at least read
> "Managing 12 volts" now and learned the difference between an open and
> short
> circuit.
>
> Actually, I know the gauge works properly because I have overheated the
> van in the past..with the gauge indicating so and checked with an infared
> thermometer. I think my thermostat may be misbehaving some..it was never
> replaced, and I am in doubt now about the pressure tank cap and hose to
> the
> overflow tank.. Though I suppose that little resistor could be acting up
> on
> my cluster foil...
> I am going to check the big mechanical things first, but I appreciate you
> taking the time to respond with the electrical diagnostic advice.
> Don Hanson
>
> On Mon, Apr 19, 2010 at 5:23 PM, David Beierl <dbeierl@attglobal.net>
> wrote:
>
>> At 12:18 PM 4/19/2010, Don Hanson wrote:
>>
>>> 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
>>>
>>
>> <snip>
>>
>> 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'
>>>
>>
>> Don, the gauge is reading so low that it's hard to know what it means in
>> terms of temperature difference. Meters and gauges are much less
>> accurate
>> below about 1/3 of full scale. I suspect the engine sender has different
>> specs than the WBX sender. To check the gauge itself and the wiring,
>> disconnect the sender and substitute 265 (100/100/68, 5% half or quarter
>> watt) ohms to read right on that second line that shows the upper bound
>> of
>> the "transition zone" and 35 ohms (10/10/15) to read at the line
>> beginning
>> the overheat zone with the light blinking. The gauge takes a couple
>> minutes
>> to stabilize, especially at the bottom.
>>
>> Yours,
>> David
>>
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