V6 Head Gasket Replacement

["Rich Wagner" <drsavage@xxxxxxx>]

Kevin Fillip asked about the difficulty of replacing head gaskets on his
'88 Milano:

Kevin, I replaced the gaskets on my GTV6 just a few months ago, and so the
process is still very fresh in my mind.  While the process isn't overly
complicated, and doesn't require special tools, it is tedious and does
require a lot of time.  If you have no experience doing this kind of work,
and need the car for transportation, I suggest biting the bullet (before
your wife can chamber it), and taking it to a reputable mechanic.  Expect
to pay about $1,800 for both gaskets.  If you have no experience but are
feeling brave, I believe that you can complete the proceedure with a lot of
help from your friends.  If you have some experience, all the better.

I am an experienced mechanic, but had never done this job on a GTV6 before.
 To replace the driver's side head gasket and install a new, mechanical
tensioner required about 32 hours of labor.  To do both heads, I would
estimate about 40 hours.  To do just the passenger side head, I would
estimate about 28 hours.

Again, you have to be brave if you are going to approach this job yourself.
 You will be dismantling a great deal of the mechanicals in the engine
compartment.  The special tools you will need are:

- -  1-5/8" socket to turn the engine by the crank
- -  A pair of outside snap ring pliers
- -  A deep 19 mm socket
- -  A torque wrench accurate around 75 ft-lb
- -  A roll of masking tape and pen or pencil
- -  You will also need the full range of metric sockets and combination
wrenches

While you're in there, you should check and replace the timing belt
tensioner, if necessary, and replace the coolant pump--even if it shows no
signs of failure.  You should also replace the drive belts, since you'll
have clear access to them.  You'll also be installing a new timing belt. 
Do not reuse the old one.  You don't have to replace the coolant hoses, but
you should if you can afford it.

Begin the job by putting the front of the car up on ramps.  Disconnect the
battery.  Next, remove the hood.  You'll want complete access, even to the
back of the engine.  Drain the coolant.  Remove the coolant hoses and the
radiator.  Now that you've got clear access to the crank, put the car in
neutral and turn the engine, using the 1-5/8" socket, to cylinder 1 TDC. 
Put the car back in gear.  Remove the drive belts.  Begin removing the
sensor wires from the thermostat housing.  Use the masking tape to label
each wire, so that you can reconnect it to its correct sensor.  Undo and
remove the timing belt covers.  The pass. side can be difficult.  You may
want to remove the interfering sensor from the thermostat housing.  Loosen
and remove the timing belt tensioner.  Remove the timing belt.  Throw it
out.  If you take my advice and replace the coolant pump, remove it now. 
The whole front of the engine should now be exposed.  Disconnect the air
flow meter (wires and large hose), and remove the whole airbox assembly. 
Undo all of the air plumbing from the engine.  Label any hoses whose
address you may forget.  Undo the large intake  hose from the plenum, and
remove the whole air plumbing mess as an assembly.  Disconnect the injector
wires from the injectors.  Undo the clamps holding the intake runner hoses
to the plenum.  Lift the plenum off of the runners, and lean it back,
against the windshield.  Undo the small bolts fixing the injectors to the
heads.  Lift the metal fuel delivery line and the injectors, as an
assembly, away from the engine and set it aside on the pass. side fender. 
This will probably end your first day of work.

If you are replacing the driver's side, the fun begins now.  Remove the
driver's seat.  I know, I know, just do it.  You'll thank me later.  Lay on
your back, under the dash.  Disconnect the brake pedal from the master
cylinder.  Undo the nuts fixing the master cylinder to the firewall.  This
is slow, tedious, and painful.  Admit to yourself that it's going to take a
while.  After you get the nuts off, go inside, have a beer, and make your
chiropractor appointment.  Next, undo the brake lines from the master
cylinder, and set the master cylinder aside.

The following process is the same for both heads:  Crawl under the car and
loosen (just loosen) the nuts connecting the exhaust to the header.  Mine
weren't frozen in place.  If yours are, soak them with penetrating oil the
day before.  Next, remove the nuts and bolts fixing the exhaust header to
the head.  Again, mine weren't frozen.  If yours are, soak them with
penetrating oil the day before.  Pull the exhaust header away from the
head.  Let it rest against the inner fender.  Remove the valve cover. 
Begin undoing the nuts fixing the head to the engine.  Undo them in reverse
order, about a turn at a time.  After the nuts are off, the head will
likely move a little when you
pull on it.  It will also likely stick a little when you pull on it.  Apply
force as needed to free the head from the block, and after 20 minutes or so
of struggling, lift the head away.  Once either head is off, be ABSOLUTELY
sure that the engine does not turn.  Don't disturb the crankshaft in any
way.  Don't even look at it.  Since the head is off, clean it up--inside
and out--using your favorite degreaser.  Take it inside, put it on the
bench, and check the valve clearances too.  Adjust as necessary.  Make sure
that the mating surface is surgically clean.  Use a razor blade or x-acto
knife to remove any offending debris.  Leave no bits of old gasket or dirt.
 Make sure that there is no oil on the surface.  If you want to be really
sure there's no oil on it, wipe the surface with isopropal alchohol just
before reinstallation.  Do the same thorough cleaning for the mating
surface of the engine block.  Your car probably came with a single piece
gasket, but if it didn't, remove the metal, flame-proof rings from the tops
of the cylinder liners.  Make sure the the tops of the liners are also
surgically clean.  Lay the new gasket in place.  Apply nothing to the
gasket.  Slide the head down over the studs, making sure, visually,  that
it's seated on the gasket.  Replace the nuts and tighten, in steps, and in
order, to spec.--72 ft-lbs, if I remember correctly.

As they always--too easily--say, assembly is the reverse.  It's best to
leave the valve covers off until you've installed the NEW timing belt. 
You'll need to see the timing marks on the cams to ensure that you've got
the whole deal set up correctly.  Also, turn the engine over by hand after
installing and tensioning the belt.  You want to make sure that there is no
interference before unleashing the starter.  If you feel any
interference--in other words, if something feels jammed--you've mistimed
the engine.  Turn it backwards to TDC again, and start over.  While
everything is apart, you may also want to replace a few more items that
age:  the injector seals (cheap, do it), vacuum lines (cheap, do it), and
coolant lines from the thermostat housing to the heads (also cheap). 
Assembly will take about as long as disassembly, so when you're ready to
put the head back on, you're halfway through the job.

After everything is back together, start the engine and let it run until up
to operating temp.  Let it cool overnight, and retorque the head--dead
cold--in the morning.

Take your time with this job.  It can be difficult and a bit overwhelming. 
However, if you keep your head about you, take a break when you get
overwhelmed, and talk to your Alfa friends for advice, you'll get through
it.  And you'll be better off for the experience.


Rich
Manitou Springs, CO
'82 GTV6 Balocco

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End of alfa-digest V7 #334
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