Date: Sat, 7 Mar 2009 12:33:02 -0500
Reply-To: David Milo <dellaone@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: David Milo <dellaone@GMAIL.COM>
Subject: Re: Takes a darn long time for the heater to come up to speed
In-Reply-To: <49B2A47E.6090504@gmail.com>
Content-Type: text/plain; charset=ISO-8859-1
The Subaru uses a "water manifold" on the top of the engine case, connecting
both left and right water jackets and other passage ways around the
cylinders. Both the ecu's sensor and the temp gauge sensor are installed in
this manifold, approximately half way along it's length. One end of the
water manifold connects to the hose going directly to the heater core, the
other bigger end is connected to the hose going to the radiator.
Circulation is always occurring through the heater core due to the water
pump. Coolant travels from the water manifold through the heater core and
back out to the water pump housing, where it flows over the temp sensing
bulb of the thermostat (at the bottom of the engine) and thereby right back
into the engine for another trip past the water jackets and passages and
back into the water manifold, etc.
No thermostat opening will occur until the thermostat sensing bulb sees
enough heat and then it will open the thermostat a little, causing some flow
to now occur from the big end of the water manifold to the radiator. When
enough cooler coolant has entered the engine through the radiator return
hose at the bottom of the engine, the thermostat will start to close again.
It is said that Subaru's "sip" coolant (through the thermostat) as the
engine goes through it's thermal cycle.
I'll stop now, NVC.
Dave
On Sat, Mar 7, 2009 at 11:44 AM, Rocket J Squirrel <
camping.elliott@gmail.com> wrote:
> Interesting! And were is the Subaru's temp gauge sender located in
> relation to the 1.9l's? Is one is a better spot to more quickly "see"
> the rise in engine temp?
>
> --
> Mike "Rocket J Squirrel" Elliott
> 84 Westfalia: Mellow Yellow ("The Electrical Banana")
> 74 Utility Trailer. Ladybug Trailer, Inc., San Juan Capistrano
> Bend, OR
> KG6RCR
>
>
>
>
> On 3/7/2009 8:16 AM David Milo wrote:
>
>> Aside from the length of the hoses, the other subtle difference is
>> that the Subaru system mixes air to control the temperature in the
>> mixing / distribution box, whereas the Vanagon was designed to use a
>> manually controlled coolant modulating valve (yes, even in the rear)
>> controlling flow through the heater core to control temperature. In
>> the Vanagon, you can almost (but not quite) completely shut off flow
>> through the heater cores.
>>
>> In the Subaru, the coolant flow through the heater core is constant,
>> and is actually the coolant circuit that modulates the thermostat
>> (located on the bottom of the engine, return hose from the radiator).
>> As others have pointed out, it is much better protected from the elements.
>>
>> Dave
>>
>> On Sat, Mar 7, 2009 at 10:16 AM, Rocket J Squirrel
>> <camping.elliott@gmail.com <mailto:camping.elliott@gmail.com>> wrote:
>>
>> I reckon there are two things that I need to observe: 1. the time it
>> takes for the temp gauge to start moving from the cold pin (Mrs
>> Elliott's Subaru comes up a lot sooner), and 2. how soon before one
>> starts to feel tendrils of warmed air come creeping out of the vents.
>> Again, it's much quicker in the other car. If these are significantly
>> longer time than others, like Jake, observed then something there's
>> something fishy going on. Given that the thermostat is such a pain to
>> get to on the 1.9l engine, I'll want to be fairly sure that
>> replacing it
>> is a worthwhile project.
>>
>>
>> --
>> Mike "Rocket J Squirrel" Elliott
>> 84 Westfalia: Mellow Yellow ("The Electrical Banana")
>> 74 Utility Trailer. Ladybug Trailer, Inc., San Juan Capistrano
>> Bend, OR
>> KG6RCR
>>
>>
>>
>>
>> On 3/6/2009 9:47 PM Jake de Villiers wrote:
>>
>> On account of this thread I paid attention this morning on the
>> way to work
>> in the grey van. It took about a mile at ~30 degrees F. to feel a
>> difference, about 3 for it to be warmish.
>>
>> I've noticed that the rear heater gets warm a lot quicker on
>> both vans.
>>
>> On Fri, Mar 6, 2009 at 5:35 PM, alfred bagdan <abagdan@shaw.ca
>> <mailto:abagdan@shaw.ca>> wrote:
>>
>>
>> If you have the rear heater valve open, most of the hot
>> coolant goes
>> through
>> the rear heater. Try closing the rear heater and see what
>> happens. Also
>> replace your thermostat in case it is stuck open. If the
>> temperature gauge
>> does not go up to the halfway point in cold weather, you
>> will probably have
>> to replace the thermostat to get some decent heat. Its a
>> bitch of a job,
>> but doable. When I replaced the hoses last summer I also
>> put pipe
>> insulation on the hot lines and also replaced the
>> thermostat and the water
>> pump. What a difference that made. I live in Edmonton,
>> Canada, and I
>> drove the van once this winter when it was -30C ( ~ -20F )
>> and it was warm
>> as toast inside, and didn't take long to warm up.
>>
>> Alfred
>> 85 Westy
>>
>> ----- Original Message -----
>> From: "Mark Tuovinen" <mst@AK.NET <mailto:mst@AK.NET>>
>> To: <vanagon@GERRY.VANAGON.COM
>> <mailto:vanagon@GERRY.VANAGON.COM>>
>> Sent: Friday, March 06, 2009 2:49 PM
>> Subject: Re: Takes a darn long time for the heater to come
>> up to speed
>>
>>
>> You just send her up here to drive my Syncro on a
>> cold(subzero) morning,
>>
>> she will appreciate your van much more afterward. My
>> kids ride to school
>> with a blanket over them for warmth and they are
>> wearing winter coats,
>> hats, mittens, and boots at the same time. Vanagons
>> have a rather large
>> area to warm up and the front core is a long way from
>> the heat source.
>> Though it won't cure your problem you could put pipe
>> insulation on your
>> front heater hoses under the van. This will reduce
>> the heat loss that
>> occurs before the hot coolant gets to the core.
>> Another and more
>> difficult issue to deal with is that the front heater
>> only draws air from
>> outside, it does not recirculate cabin air. Thus
>> while your heater core
>> is trying to warm the air, the air is trying to cool
>> the core. Not an
>> issue in moderate climates but those in extreme cold
>> areas suffer because
>> of it.
>>
>> Mark in AK
>>
>> ----- Original Message -----
>> From: Rocket J Squirrel <camping.elliott@GMAIL.COM
>> <mailto:camping.elliott@GMAIL.COM>>
>> Date: Thursday, March 5, 2009 4:35 pm
>> Subject: Takes a darn long time for the heater to come
>> up to speed
>> To: vanagon@GERRY.VANAGON.COM
>> <mailto:vanagon@GERRY.VANAGON.COM>
>>
>> My wife's Subaru Outback's heater is ready to put out
>> some serious therms
>>
>> in about 3 minutes of drive time. The temp gauge
>> comes up quickly,
>> whereas the temp gauge in ol' Mellow Yellow needs
>> another 5-8 minutes of
>> driving in freezing temps to really start to creep
>> upwards and for the
>> heater to start doing anything interesting.
>>
>> I'd like to think that the difference is due to
>> the awesome efficiency of
>> the WBX engine . . . I'd like to think that, but
>> something tells me that
>> a 2006 Subaru engine is a tad more efficient. So,
>> does anyone have any
>> idea why the 1.9L engine is so sluggish compared
>> with the Outback's
>> engine when it comes to making hot water available
>> to the heater core?
>> Mrs Squirrel gripes about how long it takes to get
>> warm air to come out
>> the heater and I'd like to have some
>> highly-technical answer to respond
>> with. You know, baffle them with BS?
>>
>> --
>> Mike "Rocket J Squirrel" Elliott
>> 84 Westfalia: Mellow Yellow ("The Electrical Banana")
>> 74 Utility Trailer. Ladybug Trailer, Inc., San
>> Juan Capistrano
>> Bend, OR
>> KG6RCR
>>
>>
>>
>>
>>
>> --
>> Jake
>>
>> 1984 Vanagon GL
>> 1986 Westy Weekender "Dixie"
>>
>> Crescent Beach, BC
>>
>> www.crescentbeachguitar.com <http://www.crescentbeachguitar.com>
>> http://subyjake.googlepages.com/mydixiedarlin%27
>>
>>
>>
>>
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