any advice for changing valve guide seals? 90 Civic Ex 1.6L 5spd

I have a little puff of blue smoke on startup, none while it's being
driven. I've been told this indicates worn valve guide seals and that
it's possible to change the seals with the head on the block. Anyone
ever done this? I've seen it discussed here, something about using
compressed air to hold valves open or something like that, don't really
know where to start though. My manual says head needs to come off, but
I don't think it's bad enough right now to get into that much work.

Thanks
-Bruce

Bruce wrote:
> I have a little puff of blue smoke on startup, none while it's being
> driven. I've been told this indicates worn valve guide seals and that
> it's possible to change the seals with the head on the block. Anyone
> ever done this? I've seen it discussed here, something about using
> compressed air to hold valves open or something like that, don't really
> know where to start though. My manual says head needs to come off, but
> I don't think it's bad enough right now to get into that much work.
>
> Thanks
> -Bruce
>
i've seen it done with the head in place - but i'd never do it on a car
i owned or where i had any liability. i don't recommend it.

but, basically you get the piston of the relevant cylinder to top dead
center, then using a deep drive socket, [gently] hammer the spring
retainer at the top of the valve. this will [eventually] dislodge the
keepers because the valve strikes the piston crown and the retainer
moves on the shaft of the valve & the keepers shake loose. they can
also drop down into oil passages, but hey, as you're not changing the
seals this way, it's not a problem, right? once the keepers & retainers
are out, you can remove the springs, pop the seals off, replace with new
ones, and ponder about how to replace the springs/retainers/keepers.
leverage with an improvised tool of some kind is the way to go, but
you'll have to figure that one out when you get there.

bottom line, removing the head sounds like apita, but really, it's the
only way to ensure the job's done safely, with minimal chance of loss or
damage to the car or yourself.

and if you drop valve springs on the floor, disgard them. any slight
damage to the surface of the wire will cause fatigue, failure and valve
strike while the engine is running.

I understand with a little effort you can do each cylinder one at a time by
going to TDC (each cyl)
& remove that spark plug.. LOCK the cam or engine. remove the spark plug &
RIG what it takes to put 100+ psi in the cylinder, keeping it there. (so,
you WILL need a compressor on it) .. After getting that use a rented valve
compression spring tool & do 1 cyl at a time.. long as you KEEP those
valves closed with that compressor
Its not a risky job... Any of you old timers out there familiar with this
approach fill in any wrinkles i may have left out.... bottledoctor
~~~~~~~~~~~~~~~~~~~~~~~~~~

bottledoctor wrote:
> I understand with a little effort you can do each cylinder one at a time by
> going to TDC (each cyl)
> & remove that spark plug.. LOCK the cam or engine. remove the spark plug &
> RIG what it takes to put 100+ psi in the cylinder, keeping it there. (so,
> you WILL need a compressor on it) .. After getting that use a rented valve
> compression spring tool & do 1 cyl at a time.. long as you KEEP those
> valves closed with that compressor
> Its not a risky job... Any of you old timers out there familiar with this
> approach fill in any wrinkles i may have left out.... bottledoctor
> ~~~~~~~~~~~~~~~~~~~~~~~~~~
>
some lever-type spring tools may do it, like this:
http://www.etoolcart.com/index.asp?P...OD&ProdID=2069

but the bona-fide tool is the c-clamp style which requires head removal,
like this:
http://www.etoolcart.com/index.asp?P...OD&ProdID=7001

compressed air is unnecessary. the valves are real close to the
pistons, so they soon touch and you can free the valve keepers once
contact is made.

"Bruce" > wrote in message ps.com...

> I have a little puff of blue smoke on startup, none while it's being
> driven. I've been told this indicates worn valve guide seals and that
> it's possible to change the seals with the head on the block. Anyone
> ever done this? I've seen it discussed here, something about using
> compressed air to hold valves open or something like that, don't really
> know where to start though. My manual says head needs to come off, but
> I don't think it's bad enough right now to get into that much work.

I've done this a few times with the head on the block. The tools I'd
used are pretty practical and safe.

1. Rope
2. Y fork tool. Looks like a tuning fork with a flat head tip

Run the rope into the cylinder. Turn the crank shaft nearly
to TDC. This tightens the valves against the head. Remove the
camshaft but put the bolts back in. Using the tuning fork (in
conjunction to the bolts) lever the spring downwards, or compress
the spring (no need to hammer on the springs, tends to loose the
keepers & retainers.) With tweezers, remove the keepers &
retainers. Install in the reverse procedure.

If the valve stems are leaking I would assume the worse. Since
the head is presumbly overheated at some point, I would check the
compression. If it's under spec, I would remove the head and do it the
right way. But, installing the head requires some precision in order
to have the gasket last the life of the car.