Date: Mon, 17 Aug 2009 16:25:38 -0700
Reply-To: Rocket J Squirrel <camping.elliott@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Rocket J Squirrel <camping.elliott@GMAIL.COM>
Subject: Re: Not quite a backfire . . .
In-Reply-To: <01ea01ca1f8e$958021e0$6501a8c0@PROSPERITY>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Oh, I reckon the Bavarian Alps provide plenty of long descents!
Two-circuit method makes sense to me.
On a not-cold day, 10 minutes of steady driving is about right to bring
the temp gauge up to running temp. Alas, when I ordered my replacement
thermostat in late 2007/early 2008 (the German kind) the shop (forget who,
won't slam anyone w/o checking, did post who in 2008 sometime) "kindly"
sent the lower temperature version, thinking they were doing me a deal. I
didn't check the paperwork closely, not until I noticed that the meter
didn't read quite as high when the engine was up to temp. I know the
higher-temperature one is the more better one, so I have to swap the dang
thang out, which is no Swiss picnic on a 1.9l. Esp. when one is one-legged
for the near duration.
Shop in town will do it for $125. Might take them up on it, since I don't
see any other way to make the swap near-term.
--
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 8/17/2009 4:00 PM Scott Daniel - Turbovans wrote:
> some thoughts :
> your vanagon uses a 'two door' thermostat.
> Old fashioned t-stats had only affect one circuit. Most modern ones
> affect two circuits. The engine starts out cold with the bypass circuit
> open, and the main coolant pipes and circuit closed.
> The idea behind the bypass circuit is to keep coolant flowing around
> and around in the engine ( and heater circuit - those are always
> 'un-thermostated ) during the warm up phase.
> Gradually, the main part opens, and the bypass part closes.
> This tends to keep the engine temp up when the main circuit is closed
> I'd think......and to even out the temp within the engine during the
> warm up phase.
>
> And, with no fuel being added, and the van driving the engine.....hardly
> any heat would be generated, so having a low reading must be pretty
> normal on long descents at zero throttle evidently.
>
> how well does it warm up from cold ?
> My 85 Wolfsburg with auto trans, get to full temp on the level, during
> other-than-winter temps pretty quickly ......like under 10 minutes.
> Does yours take a long time to get to mid-range on the gauge ?
> if it does........like takes 20 minutes at least, I'd be thinking about
> the t-stat. I only use good german ones, the 87 degree C one.
>
> I like your basic theory, about the oil-fouled plug not firing at first,
> fuel getting into the exhaust, some small backfire like sounds, then
> starting to run on all 4 again. Totally logical thinking in my opinion.
> what do the plugs look like ?
> what kind are they ? how are the plug wires etc ?
>
> We'll have to start watching temp gauges a lot more on 'no throttle'
> long decants. We don't get to do that too often, especially for 20 or
> more minutes at a time.
> Maybe there are no opportunities to do that anywhere in Germany !!
> lol.
>
>
> ----- Original Message ----- From: "Rocket J Squirrel"
> <camping.elliott@gmail.com>
> To: "Scott Daniel - Turbovans" <scottdaniel@turbovans.com>
> Cc: <vanagon@GERRY.VANAGON.COM>
> Sent: Monday, August 17, 2009 2:00 PM
> Subject: Re: Not quite a backfire . . .
>
>
>> On 8/17/2009 12:57 PM Scott Daniel - Turbovans wrote:
>>
>>> I think you have a 1.9 waterbxoer engine.
>>> if so, the temp gauge sender, a single wire sensor, is on the
>>> thermostat housing.
>>> And it's on the return hose, and seems that it would be on the colder
>>> side of the t-stat, I believe.
>>
>> So if the engine stops getting fuel, it will cool down, and the thermo
>> would close. The coolant would stop flowing (?) past the temp gauge
>> sender -- would it just pool there? Without a source of heat that
>> chunk of t-stat might get pretty cool? Just guessing.
>>
>>> The temp sensor for the fuel injection is also right there too, and
>>> you'd think they would be pretty careful about where they put that
>>> sensor.
>>
>> Yeah, dunno if they considered long descents with foot off gas and
>> cool outside temps, though.
>>
>>> low 50's ambient........it could very well be that dropping to very
>>> low temp on the gauge is normal under those conditions.
>>> I have driven up and down both sides of that pass, and I sure don't
>>> remember seeing the temp drop way off on the steep west side decent.
>>
>> Of course it would be helpful for someone else to do a long drop (20
>> to 30 minutes) in cool temps using the engine for braking, i.e., foot
>> off gas for like, 95%, of the time. 2nd gear on AT, for me, and report
>> back on what their temp gauge says. Such a person would of course need
>> to live someplace mountainous, and have nothing better to do.
>>
>>> Last time I was there was about a year ago, in an 83 Westy, with 2.1
>>> engine running the 1.9 cooling system. I sure don't think my temp
>>> needle dropped to near zero,
>>> but ......whatever !
>>
>> Well, yeah, it's not like I'm an expert on these -- or any -- engines.
>> It's entirely possible that I have had two defective thermostats. The
>> first was replaced when doing the water pump just because of this long
>> downhill in gear no fuel cool temps cooling issue. Just to see if it
>> made a difference. It didn't and on or around that time the list sort
>> of reached agreement that what I was seeing might be normal under such
>> conditions. So I've given it no further thought. It was the engine
>> miss that caught my attention and I had to think about it for a bit --
>> even while writing my post -- to figure out what I think happened: a
>> fouled plug.
>>
>> Does it sound reasonable that an engine spinning at 2k-3k rpm for
>> 10-20 minutes, with fuel cut off, could get an oil-gunked plug that
>> needs a few sprays of gasoline to unfoul it? Last time the compression
>> was tested (2008) the cylinders were in the quite reasonable range.
>> 79,000 miles.
>>
>> --
>> Mike "Rocket J Squirrel" Elliott
>> 84 Westfalia: Mellow Yellow ("The Electrical Banana")
>> 74 Utility Trailer. Ladybug Trailer, Inc., San Juan Capistrano
>> Bend, OR
>> KG6RCR
>>
>>> thanks for the note back.
>>> Scott
>>> ----- Original Message ----- From: "Rocket J Squirrel"
>>> <camping.elliott@GMAIL.COM>
>>> To: <vanagon@GERRY.VANAGON.COM>
>>> Sent: Monday, August 17, 2009 12:39 PM
>>> Subject: Re: Not quite a backfire . . .
>>>
>>>
>>>> On 8/17/2009 11:36 AM Scott Daniel - Turbovans wrote:
>>>>
>>>>> The coolant temp should not drop to a very low reading during a long
>>>>> descent in the summer.
>>>>
>>>>> I would be thinking about a thermostat not working correctly if I saw
>>>>> that on one of my vans.
>>>>> This is the main thing I wanted to comment on.
>>>>
>>>> With no pressure on the gas pedal, the fuel is totally shut off, so the
>>>> engine is not firing on any cylinders and after about 20 minutes
>>>> with cool
>>>> air blowing past it, it will lose heat. I first observed this in
>>>> 2007/2008
>>>> on the long drop down from Laguna Mountain in San Diego county and
>>>> there
>>>> was quite a lot of to and fro on this matter until the list sorted this
>>>> out as being basically an off engine in cold air being spun by its
>>>> crankshaft. This is the second thermostat, and the behavior is the
>>>> same.
>>>> It was probably in the low-50's outside, and that's cool enough to suck
>>>> heat out of the engine quickly. The Laguna Mountain descents were in
>>>> the
>>>> 30's and lasted 20 or 30 minutes. I don't think an engine can stay warm
>>>> with no fuel when driving @ 40 mph and spinning at 2,000 to 3,000
>>>> rpm very
>>>> long.
>>>>
>>>> Where does the thermal sensor for the dash gauge sit w/r/t the
>>>> thermostat?
>>>> engine side or rad side? Gotta be the engine side -- right?
>>>>
>>>>> re
>>>>> With no fuel in the cylinders for so long, a
>>>>>> plug got fouled with oil. Unburned fuel got into the exhaust
>>>>>> manifold and
>>>>>> ignited there, causing the mild explosions we heard.
>>>>>
>>>>> Yes....backfire like sounds can be from fuel in the exhaust system
>>>>> getting ignited.
>>>>> however, by your own logic and indications observed ( 02 meter ) you
>>>>> believe that the throttle switch shut off all fuel to the injectors,
>>>>> so how could there be unburned fuel in the exhaust system, if that
>>>>> were
>>>>> true ?
>>>>>
>>>>
>>>> Ya didn't read my post well enough. When we hit the flat Mrs Squirrel
>>>> pressed lightly on the gas pedal, which would start gas going into the
>>>> intake. Any cylinder with a fouled plug, due to long downhill @
>>>> 2,000 to
>>>> 3,000 rpm and no gas, would send that unburned fuel into the exhaust
>>>> manifold. To go "cough" as it popped out there.
>>>>
>>>>> that sure is a special area.
>>>>> They only just opened McKenzie Pass *now* ?? In August ?
>>>>
>>>> It's true -- they were re-paving it and now they are re-striping it.
>>>> I am certain that the re-paving was needed due to a$$holes like that
>>>> Jack
>>>> Elliott fellow driving inappropriate vehicles over the pass. See
>>>> http://socal2bend.blogspot.com/2008/08/massive-trucks-migrate-to-eugene.html
>>>>
>>>>
>>>>> on the Eugene ( west ) side of the pass, about a mile or so from the
>>>>> pass itself, on the north side of the road, is a delightful small lake
>>>>> with some campsites around it. Always wanted to camp there once.
>>>>> There is also in that area, another *really* nice little lake, with
>>>>> free unrestricted camping, with campsites around the lake.
>>>>
>>>> Yes sir, I agree. I gotta get me some Forest Service maps pronto -- the
>>>> area is peppered with intriguing places to camp. Right now, being
>>>> stuck in
>>>> a wheelchair, I gotta stick to more developed places. Which suck,
>>>> but we
>>>> gotta work with the present conditions.
>>>>
>>>> --
>>>> Mike (aka "Jack" Elliott)
>>>> 84 Westfalia: Mellow Yellow ("The Electrical Banana")
>>>> 74 Utility Trailer. Ladybug Trailer, Inc., San Juan Capistrano
>>>> Bend, OR
>>>> KG6RCR
>>>
>
| 
