Date: Thu, 5 Sep 2013 04:34:46 -0700
Reply-To: Tom Carchrae <tom@CARCHRAE.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Tom Carchrae <tom@CARCHRAE.NET>
Subject: Re: nuts vs head gasket job
In-Reply-To: <685F1F0B-FC11-485B-8F8B-F01727EB2406@comcast.net>
Content-Type: text/plain; charset=ISO-8859-1
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
>>>>>>
>>>>>>
>>>>>>
>
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