Anybody have experience with a failed Suburu Head gasket.
  Milo was on the way from Washington to Texas and made it as
  far as SZP. Then the Soob engine had a mysterious over heating
  problem towing a trailer.

  Paul Lamar

  No experience with Soob and blown head gasket, but with a Dodge
Minivan, I  had an overheating problem that seemed 'mysterious'.

  It would overheat, and when you checked the coolant reservoir it
would be  full. When the engine cooled, the reservoir would go down
as expected.

  The problem was a small leak in the head gasket, which would put
combustion
  gas into the cylinder space, driving the coolant out of the engine
and into  the overflow reservoir.

  Bill Schertz
  KIS Cruiser #4045
  N343BS

  Bill, did you try any chemical sealants such as duraseal or steel seal?

  Paul Lamar

  Yes I have as that is my business and I rebuild 3 to 4 engines a
week, no none of those sealants will work as the problem is the
combustion pressure is pushing past the gaskets into the water
system and pushing the water out the burp tank and so there is no
way to plug the leak unless you could get the sealant into the
combustion chamber to shove it into the hole thats leaking, hate to
say it but you are best to go for a whole engine as you can mill the
heads when you replace a head gasket but you cannot mill the block
and the block warps as much or more than the heads so if you put a
new gasket on a straight head and a warped block it wont last long,
 I can do a compete long block for $1500 to $1600 depending on which
engine it is and I fix all the problems that Subaru had to make it
better than new. Give me a call if you need more info. Ken

  360-834-4089

I don't know which engine is in that Subaru, but my sister has one
and it had a bad head gasket and this is a known problem.  They have
an improved replacement gasket that fixes it but they didn't do a
recall and replace it on their dime.

Steve Brazil

The good news is as far as Milo and family are concerned is they
were able to plug the leak with goo. After the engine cooled off it
sucked all the coolant back out of the over flow can. That would not
have happened if the leak still existed. That is part of the
process. If the exhaust valve and intake valve is closed hot air in
the cylinder cools off causing a low pressure in the cylinder
drawing the sealant into the leak. This is somewhat of a crap shoot
as the leak must occur around the cylinder that happens to stop in
that sealed condition. Also of course the coolant itself also
contracts drawing coolant in from the over flow can.

There has been several recent breakthroughs in these stop leak type
fluids. Prior to these breakthroughs most stop leak type products
required you to purge the engine of antifreeze coolant. This is no
longer true of the better products. The other breakthrough is a
chemical reaction that is triggered by the high 400 to 500 F metal
temperatures that causes the goo to solidify in the area of the leak
but not in the radiator.

Here is the web site that claims to be the best.
It is called Steel Seal. It is a clear liquid with no particulate matter
at all. It is rather expensive at $70 and they claim to have an iron
clad patent. "The product is drawn into the damaged area and seals
the crack with a thermo-chemical bonding process."

I have not tried it on a leaking rotary yet but
it sounds promising to fix the shrunk rotor housing problem due to
extreme over heating of the rotary. Milo has some on order to test
it on the soob if the stuff we actually used fails.

https://secure.steelseal.com/index.php/t2b

Paul Lamar



Aluminum heads on iron blocks have a problem with the different expansion
rates and amount. Each heat and cooling cycle, the gasket gets rubbed between
the different expanding and contracting surfaces. Eventually the gasket fails.
If you replace it before long there may be no wear to the aluminum parts. It
is a matter of expansion cycles and not necessarily mileage. A vehicle that is
driven short trips and allowed to cool will experience the failure sooner than
a vehicle that has longer trips before experiencing another expansion cycle.
Aluminum blocks and aluminum heads reduces the expansion problem some, BUT
casting problems can bring expansion problems into play. All manufacturers
have had some problems with this and newer gaskets are an improvement and
should last longer.
As a journeyman technician, I do not have a lot of faith in repairs in a
bottle. The reason the coolant sucked back into the cooling system is that the
source of the pressure leak at this time is very small and requires combustion
pressure to force gases into the cooling system. Without the trailer the
problem may not have reared its head for a bit longer. The repair in the
bottle may get Milo back to Texas where the new gaskets can be installed as
long as the surfaces are not warped or worn at the compression seal area. A
small amount of warp in the head can be tolerated as the head will pull
straight as the bolts are torqued. With overhead cams, if you plane the head
the cam bearings are now not in alignment and puts stress on them if the head
surface was convex or concave.
I ask one other thing; does Milo want to take the chance of being broken down
in never never land (my name for in the middle of nowhere. I go out to one
part daily. An hour or two into the bush). You are then at the mercy of the
locals who may take advantage of the situation and you have no friends around.
Better to fix it proper there and then continue.

Dale Davies