89 Accord head gasket update

Well, finally got the thing back together. So far so good. No bubbles in the
radiator overflow tank and idling pretty good. I need to get it up on the
freeway and give it a good run, before I'm willing to claim victory. Thanks
for all of the help and advice.

 

You need to wait /a few years/ before claiming victory.

A well-done head gasket will go 200K miles or more, and that without the
engine eventually consuming large amounts of oil. An ineptly-done head
gasket will fail somewhat sooner.

 

glad it's working for you. you will need to "stress test" the motor to
be sure, but based on what you've described so far, it sounds like you
took the trouble to do it right.

thanks for getting back and posting your results - very important for
the archive.

 

and one more thing - you need to figure out why the gasket blew in the
first place. if the radiator leaks, that's a classic cause. the other,
and one i have personal experience of, is if the ducting and shrouds
around the engine bay have been removed. air circulation is not what it
should be, and in hot weather at high speed, the engine can get hot -
maybe not into the red, but real close. some months later, you'll
notice the gasket is leaking...

 

The cause was a leaky cooling system and a young driver that didn't
understand that, "pull it over immediately and shut it off, if the gauge
goes to hot", means just that. Not, "my exit is only another mile down the
road. Oh well, he saw how much work went into fixing it, and he had to be
without wheels for three weeks. All's well that ends well. He drove it 85
miles to school and back yesterday. I checked it over this morning and it
looks fine. What kind of "stress test" did you have in mind?

 

nice hot day, big hill, weight in the car, full throttle for a while.
pull over at the top and see if the expansion bottle is bubbling. if
not, you fixed it!

 

Excerpt from a post from rec.autos.tech, from a very knowledgeable tech who
posts there regularly:

----

"As for how to de-carbon the pistons. Here is the easy way. Turn the
crank some so the piston drops down a bit. Now coat the bore with some
grease (any kind as long as it's thick and gooey), now rotate the crank
the opposite way so the pistons pass up through the grease to TDC. Then
use a scraper to remove the carbon (NOT real hard, you don't want to
score the pistons). Now clean off all the loose crud. Once your done
rotate the crank to drop the piston down. Then clean off the grease. It
was there to stop any carbon from going down the gap and will grab any
that is on the sides of the piston.

I would check the head surface and block with a straightedge. What you
want to watch for is damage in the area where the gasket failed. Only 3
days shouldn't have done any BUT it's best to check.

Also might want to pull the valves and clean the ports and lap the
valves to make sure they seal good. Replace the valve stem seals and
throw in a new thermostat as well.

Follow the torque specs EXACTLY."

----

And this was for a cheap-ass AMC 258 straight-six. Now port that to our
high-tech Honda engines.

What you /actually/ did will probably work for a couple of years. Plus the
car will burn oil far sooner than it otherwise might.

 

better yet, since the best practice is to use solvent gasket remover,
that stuff works great on cleaning piston crowns too. no crusty debris.

that's obvious.

unless there's a valve leaking, that's actually not a good idea for the
same reason you shouldn't use abrasives cleaning the head or block.

a new thermostat is a must. genuine oem.

indeed. bending beam torque wrench. motor oil lube on the threads. if
the threads are rusted or sticky, torque spec can go out the window, so
make sure everything's cleaned up and that the bolts turn freely under
load. chase the threads or even replace the bolts if necessary.

that doesn't have to be true. if you meticulously don't use abrasives
[no carborundum or scotchbrite], and practice general good engine
hygiene, it won't happen.

at university i got to use electron microscopy to see the way abrasives
get stuck and embedded in otherwise "clean" surfaces. [scotchbrite is
particularly dreadful - its abrasive is long alumina spikes that embed
in everything.] anyway, to effectively remove these embedded abrasives
is very difficult, much harder than can be done under a shade tree. if
they're not used in the first place, they don't embed/remain resident
and get to rip up sliding surfaces.

there is a reason rebuilt engines only last a fraction of the time of an
original - it's all down to abrasives and hygiene.