[Vwdiesel] coolant questions
Val Christian
val at mongo.mongobird.com
Tue Dec 18 07:01:07 PST 2007
> Sorry, I didn't want to sound like a know it all.
Didn't to me. Your questions and comments were jsut fine.
> I had this problem too about 2 years ago, and decided it would be a good
> start to remove the thermostat and check. Sure enough, it was stuck shut and
> was causing the engine to boil over.
Absolutely. Thermostats fail. I've even had them fall
apart. I'll NEVER use a Standt thermostat again.
On a VW, the thermostat is such a pain to remove and get to, that
I'd only use high end / OEM units. When you can get 195F
units, although I have only found 180F as of late. I suppose
if you live in FL or other hot spots the 180 might be
better.
>
> I actually have a related question.
>
> I have been noticing, though I assume this is only due to the cold weather,
> that after my engine heats up to its normal running temp, one I reach
> highway speeds, it will cool down all the way to the point below the cold
> start temperature. Is that normal for cold weather?
Now that sounds like a stuck thermostat. I'd pull it before it
sticks the other way.
>
> On Dec 18, 2007 9:28 AM, Val Christian <val at mongo.mongobird.com> wrote:
>
> > > Wouldn't that be apparent though? A leaking head gasket would have
> > coolant
> > > seeping out of it wouldn't it? Not to say that you are wrong, I just
> > want to
> > > know so I know what I am looking at if this ever happens to me.
> >
> > No it could be internal, from the cylinder to the coolant.
> > I've seen these more often than leaking coolant to the outside.
> >
> > >
> > > It wouldn't hurt to check the thermostat wouldn't it?
> >
> > I'd agree with that. A passive IR thermometer could be
> > your friend.
> >
> >
> > >
> > > On Dec 18, 2007 9:22 AM, Val Christian <val at mongo.mongobird.com> wrote:
> > >
> > > > Your head gasket may be leaking under high pressure, probably with the
> > > > engine cold at startup. As the engine heats up, the leaking may
> > reduce.
> > > > The system stays pressurized at the cap pressure, and may depressurize
> > > > as it cools, when the gas is mostly watervapor. When it's exhaust
> > > > gases, it doesn't shrink as much when it cools. Also pockets
> > > > of gas in the engine will push the coolant out.
> > > >
> > > > You might do an experimental run with the pressure cap off, and keep
> > > > adding fluid (i'd dilute to something like 30/70h2o, to save money)
> > > > and see what happens as you idle and lightly run the engine.
> > > >
> > > > I'm thinking you're right...head gasket. Over the years Ive seen
> > dozens
> > > > of hg fail on VW, and yours is behaving that way.
> > > >
> > > > Having said all that, you want to make sure that you don't have air in
> > the
> > > > system, and that you are not getting hot spots, and that the cooling
> > > > system
> > > > gets every chance to work properly. Run it unpressurized, and top it
> > off,
> > > > and then see what happens. Meanwhile, I'd plan the HG replacement.
> > > > It's not too bad of a job, but you will probably want to have the head
> > > > serviced while it's of. With no complications, and not counting time
> > > > going to the machine shop for the head, I figure about 4 to 5 hours
> > > > for the job. First time doing it, and I'd budget 15 or 20. Perhaps
> > > > others can chime in with their experience.
> > > >
> > > > Good luck.
> > > >
> > > > ps: Forget the headgasket in a bottle repairs. Gassers may have a 8:1
> > > > vs a 22.5:1 compression ratio.
> > > >
> > > > pps: Before you pull your head, if you do, please do a compression
> > check
> > > > on a reasonably warm (100F??) engine. Then you have a baseline.
> > > >
> > > >
> > > >
> > > > >
> > > > > I had a high temp indication and found the reservoir empty. I filled
> > it
> > > > and
> > > > > still had a high temp indication. When I checked the reservoir it
> > was
> > > > under
> > > > > pressure after sitting all night and blew coolant all over the
> > ground
> > > > when I
> > > > > took off the cap. I siphoned off some coolant to get the level below
> > the
> > > > > return line from the radiator. It was real cold the next night and
> > the
> > > > gage
> > > > > said it was running hot again. When I checked he coolant, it was
> > gone
> > > > from
> > > > > the reservoir.
> > > > >
> > > > > I filled it again and started it and there is not immediate
> > pressure,
> > > > like
> > > > > I'd expect from a blown head gasket. It this how a dead thermostat
> > > > works?
> > > > >
> > > > > _______________________________________________
> > > > > Vwdiesel mailing list
> > > > > Vwdiesel at vwfans.com
> > > > > http://www.audifans.com/mailman/listinfo/vwdiesel
> > > > >
> > > >
> > > > _______________________________________________
> > > > Vwdiesel mailing list
> > > > Vwdiesel at vwfans.com
> > > > http://www.audifans.com/mailman/listinfo/vwdiesel
> > > >
> > >
> > >
> > >
> > > --
> > > Stephen T. Kraus Jr.
> > > Home: (423)NONE
> > > UB3RATL4Sf00 at gmail.com;
> > >
> > > ------=_Part_13127_26131297.1197987943409
> > > Content-Type: text/html; charset=ISO-8859-1
> > > Content-Transfer-Encoding: 7bit
> > > Content-Disposition: inline
> > >
> > > Wouldn't that be apparent though? A leaking head gasket would have
> > coolant seeping out of it wouldn't it? Not to say that you are wrong, I
> > just want to know so I know what I am looking at if this ever happens to me.
> > > <br><br>It wouldn't hurt to check the thermostat wouldn't
> > it?<br><br><div class="gmail_quote">On Dec 18, 2007 9:22 AM, Val Christian
> > <<a href="mailto:val at mongo.mongobird.com">val at mongo.mongobird.com</a>>
> > wrote:
> > > <br><blockquote class="gmail_quote" style="border-left: 1px solid
> > rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">Your
> > head gasket may be leaking under high pressure, probably with the<br>engine
> > cold at startup. As the engine heats up, the leaking may reduce.
> > > <br>The system stays pressurized at the cap pressure, and may
> > depressurize<br>as it cools, when the gas is mostly watervapor. When
> > it's exhaust<br>gases, it doesn't shrink as much when it cools.
> > Also pockets<br>
> > > of gas in the engine will push the coolant out.<br><br>You might do an
> > experimental run with the pressure cap off, and keep<br>adding fluid
> > (i'd dilute to something like 30/70h2o, to save money)<br>and see what
> > happens as you idle and lightly run the engine.
> > > <br><br>I'm thinking you're right...head gasket. Over the
> > years Ive seen dozens<br>of hg fail on VW, and yours is behaving that
> > way.<br><br>Having said all that, you want to make sure that you don't
> > have air in the
> > > <br>system, and that you are not getting hot spots, and that the cooling
> > system<br>gets every chance to work properly. Run it unpressurized,
> > and top it off,<br>and then see what happens. Meanwhile, I'd plan
> > the HG replacement.
> > > <br>It's not too bad of a job, but you will probably want to have
> > the head<br>serviced while it's of. With no complications, and not
> > counting time<br>going to the machine shop for the head, I figure about 4 to
> > 5 hours
> > > <br>for the job. First time doing it, and I'd budget 15 or 20.
> > Perhaps<br>others can chime in with their experience.<br><br>Good
> > luck.<br><br>ps: Forget the headgasket in a bottle repairs. Gassers
> > may have a 8:1<br>
> > > vs a 22.5:1 compression ratio.<br><br>pps: Before you pull your head, if
> > you do, please do a compression check<br>on a reasonably warm (100F??)
> > engine. Then you have a baseline.<br><div><div></div><div
> > class="Wj3C7c"><br>
> > > <br><br>><br>> I had a high temp indication and found the
> > reservoir empty. I filled it and<br>> still had a high temp indication.
> > When I checked the reservoir it was under<br>> pressure after sitting all
> > night and blew coolant all over the ground when I
> > > <br>> took off the cap. I siphoned off some coolant to get the level
> > below the<br>> return line from the radiator. It was real cold the next
> > night and the gage<br>> said it was running hot again. When I checked he
> > coolant, it was gone from
> > > <br>> the reservoir.<br>><br>> I filled it again and started it
> > and there is not immediate pressure, like<br>> I'd expect from a
> > blown head gasket. It this how a dead thermostat works?<br>><br>>
> > _______________________________________________
> > > <br>> Vwdiesel mailing list<br>> <a href="mailto:
> > Vwdiesel at vwfans.com">Vwdiesel at vwfans.com</a><br>> <a href="
> > http://www.audifans.com/mailman/listinfo/vwdiesel" target="_blank">
> > http://www.audifans.com/mailman/listinfo/vwdiesel
> > >
> > </a><br>><br><br>_______________________________________________<br>Vwdiesel
> > mailing list<br><a href="mailto:Vwdiesel at vwfans.com">Vwdiesel at vwfans.com</a><br><a
> > href="http://www.audifans.com/mailman/listinfo/vwdiesel" target="_blank">
> > > http://www.audifans.com/mailman/listinfo/vwdiesel</a><br></div></div></blockquote></div><br><br
> > clear="all"><br>-- <br>Stephen T. Kraus Jr.<br>Home: (423)NONE<br><a
> > href="mailto:UB3RATL4Sf00 at gmail.com">UB3RATL4Sf00 at gmail.com
> > > </a>;
> > >
> > > ------=_Part_13127_26131297.1197987943409--
> > >
> >
> >
>
>
> --
> Stephen T. Kraus Jr.
> Home: (423)NONE
> UB3RATL4Sf00 at gmail.com;
>
> ------=_Part_13146_10535447.1197988364674
> Content-Type: text/html; charset=ISO-8859-1
> Content-Transfer-Encoding: 7bit
> Content-Disposition: inline
>
> Sorry, I didn't want to sound like a know it all.<br><br>I had this problem too about 2 years ago, and decided it would be a good start to remove the thermostat and check. Sure enough, it was stuck shut and was causing the engine to boil over.
> <br><br>I actually have a related question.<br><br>I have been noticing, though I assume this is only due to the cold weather, that after my engine heats up to its normal running temp, one I reach highway speeds, it will cool down all the way to the point below the cold start temperature. Is that normal for cold weather?
> <br><br><div class="gmail_quote">On Dec 18, 2007 9:28 AM, Val Christian <<a href="mailto:val at mongo.mongobird.com">val at mongo.mongobird.com</a>> wrote:<br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
> <div class="Ih2E3d">> Wouldn't that be apparent though? A leaking head gasket would have coolant<br>> seeping out of it wouldn't it? Not to say that you are wrong, I just want to<br>> know so I know what I am looking at if this ever happens to me.
> <br><br></div> No it could be internal, from the cylinder to the coolant.<br> I've seen these more often than leaking coolant to the outside.<br><div class="Ih2E3d"><br>><br>> It wouldn't hurt to check the thermostat wouldn't it?
> <br><br></div> I'd agree with that. A passive IR thermometer could be<br> your friend.<br><div><div></div><div class="Wj3C7c"><br><br>><br>> On Dec 18, 2007 9:22 AM, Val Christian <<a href="mailto:val at mongo.mongobird.com">
> val at mongo.mongobird.com</a>> wrote:<br>><br>> > Your head gasket may be leaking under high pressure, probably with the<br>> > engine cold at startup. As the engine heats up, the leaking may reduce.<br>> > The system stays pressurized at the cap pressure, and may depressurize
> <br>> > as it cools, when the gas is mostly watervapor. When it's exhaust<br>> > gases, it doesn't shrink as much when it cools. Also pockets<br>> > of gas in the engine will push the coolant out.
> <br>> ><br>> > You might do an experimental run with the pressure cap off, and keep<br>> > adding fluid (i'd dilute to something like 30/70h2o, to save money)<br>> > and see what happens as you idle and lightly run the engine.
> <br>> ><br>> > I'm thinking you're right...head gasket. Over the years Ive seen dozens<br>> > of hg fail on VW, and yours is behaving that way.<br>> ><br>> > Having said all that, you want to make sure that you don't have air in the
> <br>> > system, and that you are not getting hot spots, and that the cooling<br>> > system<br>> > gets every chance to work properly. Run it unpressurized, and top it off,<br>> > and then see what happens. Meanwhile, I'd plan the HG replacement.
> <br>> > It's not too bad of a job, but you will probably want to have the head<br>> > serviced while it's of. With no complications, and not counting time<br>> > going to the machine shop for the head, I figure about 4 to 5 hours
> <br>> > for the job. First time doing it, and I'd budget 15 or 20. Perhaps<br>> > others can chime in with their experience.<br>> ><br>> > Good luck.<br>> ><br>> > ps: Forget the headgasket in a bottle repairs. Gassers may have a 8:1
> <br>> > vs a 22.5:1 compression ratio.<br>> ><br>> > pps: Before you pull your head, if you do, please do a compression check<br>> > on a reasonably warm (100F??) engine. Then you have a baseline.
> <br>> ><br>> ><br>> ><br>> > ><br>> > > I had a high temp indication and found the reservoir empty. I filled it<br>> > and<br>> > > still had a high temp indication. When I checked the reservoir it was
> <br>> > under<br>> > > pressure after sitting all night and blew coolant all over the ground<br>> > when I<br>> > > took off the cap. I siphoned off some coolant to get the level below the<br>
> > > > return line from the radiator. It was real cold the next night and the<br>> > gage<br>> > > said it was running hot again. When I checked he coolant, it was gone<br>> > from<br>> > > the reservoir.
> <br>> > ><br>> > > I filled it again and started it and there is not immediate pressure,<br>> > like<br>> > > I'd expect from a blown head gasket. It this how a dead thermostat<br>> > works?
> <br>> > ><br>> > > _______________________________________________<br>> > > Vwdiesel mailing list<br>> > > <a href="mailto:Vwdiesel at vwfans.com">Vwdiesel at vwfans.com</a><br>> > >
> <a href="http://www.audifans.com/mailman/listinfo/vwdiesel" target="_blank">http://www.audifans.com/mailman/listinfo/vwdiesel</a><br>> > ><br>> ><br>> > _______________________________________________
> <br>> > Vwdiesel mailing list<br>> > <a href="mailto:Vwdiesel at vwfans.com">Vwdiesel at vwfans.com</a><br>> > <a href="http://www.audifans.com/mailman/listinfo/vwdiesel" target="_blank">http://www.audifans.com/mailman/listinfo/vwdiesel
> </a><br>> ><br>><br>><br>><br>> --<br>> Stephen T. Kraus Jr.<br>> Home: (423)NONE<br>> <a href="mailto:UB3RATL4Sf00 at gmail.com">UB3RATL4Sf00 at gmail.com</a>;<br>><br></div></div>> ------=_Part_13127_26131297.1197987943409
> <br>> Content-Type: text/html; charset=ISO-8859-1<br>> Content-Transfer-Encoding: 7bit<br>> Content-Disposition: inline<br>><br>> Wouldn&#39;t that be apparent though? A leaking head gasket would have coolant seeping out of it wouldn&#39;t it? Not to say that you are wrong, I just want to know so I know what I am looking at if this ever happens to me.
> <br>> <br><br>It wouldn&#39;t hurt to check the thermostat wouldn&#39;t it?<br><br><div class="gmail_quote">On Dec 18, 2007 9:22 AM, Val Christian &lt;<a href="mailto:
> <a href="mailto:val at mongo.mongobird.com">val at mongo.mongobird.com</a>"><a href="mailto:val at mongo.mongobird.com">val at mongo.mongobird.com</a></a>&gt; wrote:<br>> <br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt
> 0.8ex; padding-left: 1ex;">Your head gasket may be leaking under high pressure, probably with the<br>engine cold at startup. &nbsp;As the engine heats up, the leaking may reduce.<br>> <br>The system stays pressurized at the cap pressure, and may depressurize<br>as it cools, when the gas is mostly watervapor. &nbsp;When it&#39;s exhaust<br>gases, it doesn&#39;t shrink as much when it cools. &nbsp;Also pockets<br>
> <br>> of gas in the engine will push the coolant out.<br><br>You might do an experimental run with the pressure cap off, and keep<br>adding fluid (i&#39;d dilute to something like 30/70h2o, to save money)<br>and see what happens as you idle and lightly run the engine.
> <br>> <br><br>I&#39;m thinking you&#39;re right...head gasket. &nbsp;Over the years Ive seen dozens<br>of hg fail on VW, and yours is behaving that way.<br><br>Having said all that, you want to make sure that you don&#39;t have air in the
> <br>> <br>system, and that you are not getting hot spots, and that the cooling system<br>gets every chance to work properly. &nbsp;Run it unpressurized, and top it off,<br>and then see what happens. &nbsp;Meanwhile, I&#39;d plan the HG replacement.
> <br>> <br>It&#39;s not too bad of a job, but you will probably want to have the head<br>serviced while it&#39;s of. &nbsp;With no complications, and not counting time<br>going to the machine shop for the head, I figure about 4 to 5 hours
> <br>> <br>for the job. &nbsp;First time doing it, and I&#39;d budget 15 or 20. &nbsp;Perhaps<br>others can chime in with their experience.<br><br>Good luck.<br><br>ps: Forget the headgasket in a bottle repairs. &nbsp;Gassers may have a 8:1<br>
> <br>> vs a 22.5:1 compression ratio.<br><br>pps: Before you pull your head, if you do, please do a compression check<br>on a reasonably warm (100F??) engine. &nbsp;Then you have a baseline.<br><div><div></div><div class="Wj3C7c"><br>
> <br>> <br><br>&gt;<br>&gt; I had a high temp indication and found the reservoir empty. I filled it and<br>&gt; still had a high temp indication. When I checked the reservoir it was under<br>&gt; pressure after sitting all night and blew coolant all over the ground when I
> <br>> <br>&gt; took off the cap. I siphoned off some coolant to get the level below the<br>&gt; return line from the radiator. It was real cold the next night and the gage<br>&gt; said it was running hot again. When I checked he coolant, it was gone from
> <br>> <br>&gt; the reservoir.<br>&gt;<br>&gt; I filled it again and started it and there is not immediate pressure, like<br>&gt; I&#39;d expect from a blown head gasket. It this how a dead thermostat works?<br>&gt;<br>&gt; _______________________________________________
> <br>> <br>&gt; Vwdiesel mailing list<br>&gt; <a href="mailto:<a href="mailto:Vwdiesel at vwfans.com">Vwdiesel at vwfans.com</a>"><a href="mailto:Vwdiesel at vwfans.com">Vwdiesel at vwfans.com</a>
> </a><br>&gt; <a href="<a href="http://www.audifans.com/mailman/listinfo/vwdiesel" target="_blank">http://www.audifans.com/mailman/listinfo/vwdiesel</a>" target="_blank"><a href="http://www.audifans.com/mailman/listinfo/vwdiesel" target="_blank">
> http://www.audifans.com/mailman/listinfo/vwdiesel</a><br>> </a><br>&gt;<br><br>_______________________________________________<br>Vwdiesel mailing list<br><a href="mailto:
> <a href="mailto:Vwdiesel at vwfans.com">Vwdiesel at vwfans.com</a>"><a href="mailto:Vwdiesel at vwfans.com">Vwdiesel at vwfans.com</a></a><br><a href="<a href="http://www.audifans.com/mailman/listinfo/vwdiesel" target="_blank">
> http://www.audifans.com/mailman/listinfo/vwdiesel</a>" target="_blank"><br>> <a href="http://www.audifans.com/mailman/listinfo/vwdiesel" target="_blank">http://www.audifans.com/mailman/listinfo/vwdiesel
> </a></a><br></div></div></blockquote></div><br><br clear="all"><br>-- <br>Stephen T. Kraus Jr.<br>Home: (423)NONE<br><a href="mailto:
> <a href="mailto:UB3RATL4Sf00 at gmail.com">UB3RATL4Sf00 at gmail.com</a>"><a href="mailto:UB3RATL4Sf00 at gmail.com">UB3RATL4Sf00 at gmail.com</a><br>> </a>;<br>><br>> ------=_Part_13127_26131297.1197987943409--
> <br>><br><br></blockquote></div><br><br clear="all"><br>-- <br>Stephen T. Kraus Jr.<br>Home: (423)NONE<br><a href="mailto:UB3RATL4Sf00 at gmail.com">UB3RATL4Sf00 at gmail.com</a>;
>
> ------=_Part_13146_10535447.1197988364674--
>
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