Removing the pistons

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Duarte - 17 Apr 2006 23:05 GMT

OK...I have another newbie question. I was able to remove the head off
my 92 accord thinking that maybe my head gasket was blown. The head
gasket actually looks in pretty good shape. I will replace anyway. Now,
the thing I would like to do is take the pistons out and
inspect/replace the rings, clean out, etc...Is this possible without
removing the whole engine and turning it upside down as the manual
states. Could I do it from the bottom if I removed the oil pan? Any
info would be appreciated.

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Michael Pardee - 18 Apr 2006 02:24 GMT

> OK...I have another newbie question. I was able to remove the head off
> my 92 accord thinking that maybe my head gasket was blown. The head
[quoted text clipped - 4 lines]
> states. Could I do it from the bottom if I removed the oil pan? Any
> info would be appreciated.

Haven't done it on a Honda engine, but the general rule is that the
crankshaft has to come out to get the pistons out the bottom.

If you don't have something known to be seriously wrong with the pistons,
for the love of your sanity leave them be. They are fine if you aren't
burning a lot of oil, and disturbing them will only make things worse. Honda
rings typically last the life of the car if you change the oil regularly and
don't make the engine "ping." If they need work it has to be done properly,
and that means big bucks.

Since the head is off, take it to a machine shop - preferably one that
specializes in cylinder heads - to have it checked for flatness and to have
the valve seals replaced. When you put the head on, be sure to follow the
instructions regarding cleanliness of the mating surfaces, tightening
sequence and torque. The head gasket and manifold gaskets must be replaced
any time the head is removed.

Mike

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Eric - 18 Apr 2006 05:10 GMT

> > OK...I have another newbie question. I was able to remove the head off
> > my 92 accord thinking that maybe my head gasket was blown. The head
[quoted text clipped - 7 lines]
> Haven't done it on a Honda engine, but the general rule is that the
> crankshaft has to come out to get the pistons out the bottom.

True if you want to get them out the bottom side of the block, but since the
head is off most folks would take them out through the top (in my
experience, Hondas rarely have a ridge at the top of the cylinder).
Typically, you just need to pull the oil pan and then remove the rod caps.
The pistons can then be removed by tapping on the rods with a wooden handle
such as a hammer handle). The caps need to go back on the same connecting
rod they came from so, if you do this, mark them with a metal scribe as you
take them out and also mark the rods.

> If you don't have something known to be seriously wrong with the pistons,
> for the love of your sanity leave them be. They are fine if you aren't
> burning a lot of oil, and disturbing them will only make things worse.

Agreed, it might be best to leave them alone unless there's a known problem.
Once you take them out, you should replace the rings and the rod bearings.
It's a lot of work and extra expense and, if it's not done right, then it
could make things worse, much worse.

In addition, if don't take the pistons out, then you'll want to put some ATF
on the top of the pistons to prevent the deposits in the ring grooves from
drying out. Use just enough to cover the tops of the pistons and remove it
before you put the head back on. Using the ATF will help prevent the motor
from burning oil after you get the head back on the block.

Lastly, one thing that I'm curious about is why the head was pulled in the
first place? Also, my rule book says to replace the thermostat when you do
the head unless it was recently done (using OE parts).

Eric

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Duarte - 18 Apr 2006 07:46 GMT

Thanks guys for your responses. I meant if I could push them up from
the bottom.

Long story short as to why I took the head out is because I was leaking
coolant into the engine (somewhere) as I was burning it. In addition
when I'm driving and stop at a light, for instance, when I try to get
going is like it has no power to get going. I accelerate and it just
goes very, very slow. I thought I had a blown head gasket, but now that
I took the head out the head the gasket actually looks OK, so now I'm
thinking I may have a broken ring or something like that which is
making me lose compression thus the slow power. Since I already went
through the trouble of taking the head out I thought if I could do it
without taking the whole engine out I might as well take out the
pistons and inspect/replace the rings.

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Grumpy AuContraire - 18 Apr 2006 12:03 GMT

> Thanks guys for your responses. I meant if I could push them up from
> the bottom.
[quoted text clipped - 10 lines]
> without taking the whole engine out I might as well take out the
> pistons and inspect/replace the rings.

Pistons with broken rings will move from side to side with pressure
applied on the top. Broken rings can be the result of detonation
(pinging) and/or excessive ring land wear.

Another note... If a head is removed on a high mileage car (150K + on a
Honda), oil consumption can be expected to increase (assuming that rings
are not replaced) due to block distortion when re-torquing the head.
This is a result of the old rings losing their seating characteristics.
Don't ask me why I know this (G).

JT

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