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
>>>>>
>>>>>
