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Date:         Wed, 4 Sep 2013 18:24:28 -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
Comments: To: Jim Felder <jim.felder@GMAIL.COM>
In-Reply-To:  <CAFnDXk3NjeWg2DyULfYe58+THHENhn4_CVSEz=Mp6HyvtBnOSA@mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed

if it's pushing coolant into the license plate bottle.. usually, the onlytwo things that would cause that are the blue pressure cap not working right.. or combustion gases getting from the combustion chambers into the coolant.

This 2nd one is a common failure mode. If head nuts were found not fully tightened ..'mabye' ..a big maybe , retorquing and resealing the nuts 'could' help. Maybe. it's a simple enough job with not a lot of effort or parts cost.. so might as well. I just wouldn't expect major transformation.

If it's the exhaust into the coolant syndrome..and one is trying to get off as lightly as possible ( do only the bad side, if it one side only ) you can isolate to one side or the other ..by commpression test, leak-down test etc. Those are not always definitive. Once in a while pulsing in the pressure bottle ( cap off ) can be observed doing a compression test ....if you luck out and see that, you know it's that cylinder. of course..the actual pressure of exploding fuel-air mixture produces a lot more pressure than is developed during a simple compression or leak down test. So 'maybe' these tests could reveal which cylinder/s , and maybe not.

Ultimately ...head or heads will have to come off.

also .....due to danger of corrosion on cylinder headstuds ...I don't like to see heads left on for say 20 years ,esepcially with not changing the coolant very much. A stud breaks off down in the block while you'regoing to unscrew a nut ..and you're screwed , literally and figuratively, right there. It doesn't happen often, but it does happen. That's serious engine problem ..and often leads to a whole new engine or serious rebuild.

lol..face it, it's due. You might as well try Nanotech 'head gasket repair' at this point, too, in an attempt to prolong the inevitable. Scott 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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