Date: Thu, 5 Sep 2013 11:29:09 -0700
Reply-To: Scott Daniel <scottdaniel@TURBOVANS.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Scott Daniel <scottdaniel@TURBOVANS.COM>
Organization: Cosmic Reminders
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; format=flowed
Hi Tom, if all you have for a ground surface is gravel, then for sure
...take the engine out.
Anice thick 4 X 8 piece of plywood makes a nice smooth surface foryour
floor jack to roll on.
If you don't have one, there are so manyuses for a floorjack.....you
really should want one. The bigger the wheels on it the better.
a stand you can rotate the engine on is nice, not quite mandatory
though. Sometimes I use one, sometimes I don't.
have fun !
scott
On 9/5/2013 4:34 AM, Tom Carchrae 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
>>>>>>>
>>>>>>>
>>>>>>>
|