Date:         Thu, 25 Jun 2020 19:48:35 -0700
Reply-To:     vw_van_fan_Mark <madvws@COX.NET>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         vw_van_fan_Mark <madvws@COX.NET>
Subject:      Re: Coolant Hoses, Complete Set -- Remove and Replace
Comments: To: Gabriel Hourtouat <ghourtouat@GMAIL.COM>
In-Reply-To:  <CAA5Wjgg0LDX_9+JioG_hjVLVHSUdtnLqVgGv+eCMh986aD+Ozw@mail.gmail.com>
Content-Type: text/plain; charset=UTF-8; format=flowed

If the coolant returning to the waterpump is really 225F then the
radiator fan should be running constantly since that is above the rad
fan temp switch shut-off temp. If the thermostat is working then the
radiator itself should measure hotter than the coolant returning to the
water pump.

So I would question whether the thermostat is fully working.
If bypass disc isn't closing off the bypass path then some coolant would
be able to skip the radiator and just keep recirculating back to the
pump. Some coolant would still go to the radiator if the main thermostat
disc was opening.

If you can measure the temp of the large rubber hose to the top of the
thermostat housing and compare it to the temp of the large rubber hose
connecting the lower housing to the waterpump feed pipe the results
should help determine what is happening. Measure the rubber in both cases.

Mark

Gabriel Hourtouat wrote:
> Celebrations cut short.  Violins start to play...
>
> Is it possible I have a bad Tstat?
> -any opinions and suggestions are MOST welcome...
>
> after more extensive driving around, engine temp is controlled well above
> what I am used to (IE (bottom 1/3 of the LED)...
> -temperature gauge:  centreline of the needle is about 1 full LED
> diameter above the centre of the LED
> -temperature scanner reads 225F on the return pipe to the water pump
>
> At idle, the coolant fan comes on and controls the temperature at this
> elevated temperature.
>
>