Date: Thu, 5 Sep 2013 09:09:04 -0700
Reply-To: Angus Gordon <birdworks@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Angus Gordon <birdworks@GMAIL.COM>
Subject: Re: nuts vs head gasket job
In-Reply-To: <CAFNeVpHKPQzC_RjQmmWc9tfSv8Z8=DKhKyZVMSySiMvP-1GESw@mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-1
Tom, the 2x4 hoist is to lower the engine down to the ground, not to hoist
it up into the vehicle. Lower it onto a piece of plywood and you can pull
that around on the gravel.
Angus
On Thu, Sep 5, 2013 at 4:34 AM, Tom Carchrae <tom@carchrae.net> wrote:
> Scott: in terms of stand or hoist - I don't have a garage. I've been
> prepared to work on the heads without removing the engine, but if I am
> going to go to the trouble of undressing the top of the engine, I may as
> well pull the engine out and have a look at the clutch and so on, and it
> sounds much easier to work on the heads if you can rotate the engine.
> Good to know that I could rig up a 2 x 4 hoist, my drive is gravel, so a
> hoist with wheels would be nearly useless. I'm thinking a 2 x 4 hoist,
> then slide it to the centre of the van, mount on a stand, and work away.
>
> And yes, there have been enough heebie geebies, although I have had several
> decent shops look at it and none have been sure it was a head gasket issue.
> It might be a cracked head that farts under load... any which way, I
> suspect the heads have had abuse and could at least use the JB beauty
> treatment on their pockmarks, if not replacement. They are AMC heads, and
> I think they've been on there for less than a decade.
>
> ORR; too right. I get awfully confused in metric imperial Canada. I grew
> up in Ireland, where the distances were in miles and speeds in KM/H - no
> wonder they produce some good mathematicians.
>
> Tom
>
>
>
>
>
>
> On Wed, Sep 4, 2013 at 9:42 PM, OlRivrRat <OlRivrRat@comcast.net> wrote:
>
> > Tom
> >
> > 220ºC = 428ºF ~ I doubt very much that your engine would have
> been
> > able to achieve that CoolentTemp ~ pretty sure it would have seized &or
> > blown all sorts of hoses off long before it got to that Temp' ~ If you
> > meant 220ºF then that's not really terrible ~ not good but not terrible ~
> >
> >
> > ORR ~ DeanB
> >
> >
> >
> > On 4 Sep , 2013, at 9:45 PM, Tom Carchrae wrote:
> >
> > Jim: I guess I got lucky - no coolant drips. But you make a good point
> >> about what a crazy system that is and why it is prone to failure.
> >>
> >> Scott: I have tried a few blue caps. I need to make a cap tester and/or
> >> run the van with a pressure gauge on the expansion tank when the van is
> >> running. (Test # 2 from
> >> http://web.archive.org/web/**20050309065156/http://www.**
> >> bostonengine.com/articles/**waterboxes.html<
> http://web.archive.org/web/20050309065156/http://www.bostonengine.com/articles/waterboxes.html
> >
> >> ).
> >> I've previously done a test for exhaust gasses, but no CO2 detected. I
> >> have wanted to plumb a pressure gauge into the cooling system for some
> >> time
> >> now - I am not brave (stupid?) enough to put it in on the dash, but I am
> >> definitely going to rig up a temporary one to the expansion tank.
> >>
> >> When I bought the van, I took it to a mechanic, who said, "hey your cap
> is
> >> bad, we changed it" - and he did some work on my heads, what I am not
> sure
> >> although it involved valve adjustment to fix low compression. After
> this,
> >> the cooling system started blowing up here and there and nearly $2k
> later
> >> I
> >> was broke and annoyed and have not returned to that mechanic. I then
> said
> >> screw this and have most of the work on the van myself since. I drove
> it
> >> across western Canada and the cooling system blew up twice more on me -
> >> after the first time, I changed the cap to another spare I had bought.
> >> The
> >> second time was due to air in the radiator and a giant traffic jam (a
> >> massive mud slide on Hwy 1) and the van actually overheated (went to
> >> ~220oC
> >> and it was full of water) and the coolant sensor popped off - its
> >> whereabouts are still unknown. Both times the van was pretty heat
> soaked
> >> and running at slow speeds - I learned a lesson there.
> >>
> >> So, yeah, it is probably due. And I actually enjoy working on it, so
> it's
> >> not all bad.
> >>
> >> Btw, are there any engine stands and hoists that are specifically
> designed
> >> for working inside your van? :)
> >>
> >> Tom
> >>
> >>
> >>
> >>
> >>
> >> On Wed, Sep 4, 2013 at 6:25 PM, Scott Daniel <scottdaniel@turbovans.com
> >*
> >> *wrote:
> >>
> >> PS to my last post.
> >>> Make sure it's not the blue pressure cap. Try another one. They are
> >>> notoriously flakey sometimes.
> >>>
> >>>
> >>>
> >>> On 9/4/2013 4:37 PM, Jim Felder wrote:
> >>>
> >>> The head bolts and the heads do two things simultaneously, and do only
> >>>> one
> >>>> of them very well.
> >>>>
> >>>> They hold the aluminum ring that serves as a true head gasket; that
> is,
> >>>> that gasket confines the compression gases to within the cylinder,
> >>>> without
> >>>> leaking it to the outside world. The other thing that is going on is
> >>>> that
> >>>> the head also squeezes a rubber gasket between the head and the water
> >>>> jacket on the block. This is imprecise. Normally, the compression head
> >>>> gaskets do not fail very often. That is not true of the outer water
> >>>> gasket
> >>>> which is held in place by the same head bolts. Think of it s a circle
> >>>> (actually two circles on each side) of metal, with very precise
> clamping
> >>>> pressure to hold in the combustion gasses, surrounded by a rubber
> gasket
> >>>> which deteriorates, holding in the coolant.
> >>>>
> >>>> Guess which is going to go first?
> >>>>
> >>>> Yep, the rubber. If your head bolts are tight enough to contain the
> >>>> combustion gasses, but you are leaking water, you are not going to
> >>>> affect
> >>>> the rubber more than a thousandths or two by tightening the already
> >>>> tight
> >>>> bolts holding the compression gaskets in place. If you are leaking
> >>>> coolant,
> >>>> it is because your rubber gaskets have a breech somewhere, not because
> >>>> there is not enough pressure on them.
> >>>>
> >>>> It always makes me feel better to go through the procedure or
> tightening
> >>>> the bolts as you suggest, but, in the end, you will have to pull the
> >>>> heads
> >>>> and replace the outer rubber gaskets.
> >>>>
> >>>> Jim
> >>>>
> >>>>
> >>>> On Wed, Sep 4, 2013 at 11:54 AM, Tom Carchrae <tom@carchrae.net>
> wrote:
> >>>>
> >>>> I've put this off long enough. I got a few trips from my van this
> >>>>
> >>>>> summer,
> >>>>> but on the last day I drove it, it backed up the coolant in the
> >>>>> reservoir
> >>>>> (behind licence plate) three times in one day. I would pull over
> when
> >>>>> the
> >>>>> blinking low-coolant light turned on, drain the coolant out into a
> >>>>> bottle,
> >>>>> start the vehicle, open the hot pressurized tank, and pour the
> coolant
> >>>>> back
> >>>>> where it belonged.
> >>>>>
> >>>>> Yesterday I took the valve covers off and used a torque wrench to
> >>>>> inspect
> >>>>> the tightness of the nuts on the heads - well, all the easy to get to
> >>>>> nuts
> >>>>> (so all but the two behind the air intake - I have only removed the
> air
> >>>>> filter box so far).
> >>>>>
> >>>>> I have only done one side so far, but I found one of the bolts in the
> >>>>> centre of the head to be slightly under spec (37lb). I recall Dennis
> >>>>> Hayes
> >>>>> saying (email below) that this managed to solve head gasket symptoms
> >>>>> 50%
> >>>>> of
> >>>>> the time if done soon enough. I doubt I have been soon enough, but
> how
> >>>>> does one tell.
> >>>>>
> >>>>> I am prepared to do the head removal but boy would I be happy if it
> was
> >>>>> as
> >>>>> simple as tightening some nuts. Would I be overly hopeful to think
> >>>>> that
> >>>>> this minimal nut tightening this late would save me having to remove
> >>>>> the
> >>>>> heads?
> >>>>>
> >>>>> Tom
> >>>>>
> >>>>> 84 Vanagon
> >>>>>
> >>>>>
> >>>>>
> >>>>>
> >>>>> On Thu, May 9, 2013 at 2:19 PM, Dennis Haynes <
> d23haynes57@hotmail.com
> >>>>> >
> >>>>> wrote:
> >>>>>
> >>>>> One problem with relying on the sniffer tests is that they are
> looking
> >>>>>
> >>>>>>
> >>>>>> for
> >>>>>
> >>>>> un-burned hydrocarbons. In order for this to work in addition to the
> >>>>>> leak
> >>>>>> you also need a combustion failure in the leaking cylinder. While
> >>>>>> cracked
> >>>>>> or
> >>>>>> loose heads may also cause a combustion issue you are in deep
> trouble
> >>>>>> by
> >>>>>> the
> >>>>>> point the sniffer tests pick it up. Keep in mind if those gasses can
> >>>>>> get
> >>>>>> out
> >>>>>> in some cases coolant can get into the cylinders. Antifreeze into
> the
> >>>>>> cylinders and then into the oil can cause some real damage. Long
> >>>>>> before
> >>>>>> antifreeze in the oil is visible the stuff becomes extremely
> corrosive
> >>>>>>
> >>>>>> and
> >>>>>
> >>>>> can quickly destroy bearings along with crank and cam surfaces. It
> can
> >>>>>>
> >>>>>> also
> >>>>>
> >>>>> destroy pistons by blowing out the tops and destroying the ring
> lands.
> >>>>>>
> >>>>>> If the engine has ever been overheated, (even before a rebuild) or
> has
> >>>>>>
> >>>>>> had
> >>>>>
> >>>>> the heads off for any reason loose heads can be the cause. I
> probably
> >>>>>>
> >>>>>> have
> >>>>>
> >>>>> a
> >>>>>> better than 50-50 success rate in fixing these issues just be
> >>>>>> retourqing
> >>>>>> the
> >>>>>> heads if the problem has not been left so long that the head seals
> >>>>>>
> >>>>>> (inners)
> >>>>>
> >>>>> or the tops of the cylinders have burned or pitted away.
> >>>>>>
> >>>>>> Dennis
> >>>>>>
> >>>>>>
> >>>>>>
> >
>
|