Below is the procedure I used to repair my blown stock headgasket. Feel free to use this advice as a reference, or if you've done the task yourself, contact me with your comments or revisions.
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Below is the procedure I used to repair my blown stock headgasket.
Feel free to use this advice as a reference, or if you've done the task
yourself, contact me with your comments or revisions.
Please note, I am not a mechanic. I have never had any official training as a mechanic. If you use the advice below, you do so at your own risk. I will not be held accountable for any communication discrepancies.
In the following process, when I say {store} I used sheets of cardboard with holes punched to hold each bolt. I used twist ties to hold each nut to the cardboard and labeled each sheet of cardboard in order to put every part in its original position.
Battery
Before you disconnect the battery, pull the EFI fuse and start the car in order to consume all the fuel in the fuel rail. Disconnect and remove the battery. Remove the hold down bolts and plastic lip below the battery.
Radiator and Fan Clutch Assembly
Drain the radiator using the draincock on the lower passenger side of the vehicle. Remove the cap to open the vacuum in the system. Collect this in a container so it can be disposed of properly. Remove the upper radiator hose. Using a flat screwdriver, remove the lower fan shroud by lifting the brass clips and sliding them back over the plastic tabs. There are two such clips. Using a 10 mm socket, remove the three bolts that hold the A.C. cooling fan to the radiator. Place the fan in the battery area. Extract the two bolts that attach the fan shroud to the radiator and remove the shroud. Using a screwdriver, loosen the clamps on the transmission oil cooling lines. Cover the ends of the transmission oil lines with saran wrap and a twist tie. Disconnect the lower radiator hose from the radiator. Remove the two clamps that hold the radiator in place and remove it. Finally, remove the four nuts that hold the fan clutch assembly onto the waterpump driveshaft using a 12 mm wrench.
Head Removal
Remove the air intake using a 10 mm socket to extract the two bolts near the filter and then loosen the clamp on the throttle body. When removing the air intake, be careful not to brake the vacuum line that connects the air flow sensor to the power steering pump.
Next, using a 12 mm open/closed end wrench, remove the six nuts and bolts that connect the throttle body to the upper intake manifold. {store} Then, using a 12 mm deep wall socket, remove the three throttle body mounting brackets and the throttle cable linkage which acts as a fourth bracket. Label and disconnect all vacuum lines from on top of the throttle body. Remove the metal EGR tubing that connects the valve covers to the throttle body. Also, remove the thermostat and its cover at this time.
Remove the alternator. One adjustment bolt and the pivot bolt. One 10 mm nut, and a plug-in clip on the back of the alternator.
Now, with the throttle body removed, use a 3/4 inch wrench to turn the crank shaft to 0 degrees or Top Dead Center. Use a 10 mm socket to remove the bolts from the upper timing belt cover. {store} Loosen the tension on the idler pulley bolt. Stretch the spring and slide the belt off the cam pulleys. Using an A.C. pulley holding tool, I held the cam pulley in place while removing the center bolt. Note the position of the metal stud that protrudes from the cam. After removing the cam pulleys, remove the back to the upper timing belt cover and {store} those bolts.
Remove each spark plug boot from the head by pulling on the boot only. Detach each of the wiring harness connectors from the thermostat housing. Remove the cam position sensor (CPS) cover with plugs attached. Now, using white out, mark the position of the pickup within the CPS relative to the edge of the CPS. Also mark the position of the adjustment bolt by painting its edge. THIS IS VERY IMPORTANT!!! Use the 12 mm wrench to remove the position bolt from the head. Remove the cam position sensor. With the CPS removed, you can see the thermostat housing. Remove the tubing that connects the coolant housing to the block. Remove the two nuts and bolt that attach the housing.
Throttle Position Sensor/Cold Start
Remove the two bolts that hold the cold start injector in place and store them in the manifold. Using a 12 mm socket, universal joint, and extension, remove the bolts and nuts that attach the upper intake manifold to the lower plenum. These are a pain in the ass to get to, but the universal joint helps. When you remove the plenum, you'll be feeling for the other bolts with your finger tips! When your removing this section of the intake, there will be a vacuum tubing bracket at the front behind the alternator, and the back rear of the manifold. You can also use the socket to remove the two bolts that connect the EGR near the rear.
Remove the valve covers by extracting the screws that attach the valve covers to the head. {store} There is a rubber hose that connects the block to the intake valve cover. Mine was brittle and had to be replaced when removed. Using a 10mm socket, remove each set of bolts from the bearing caps in a specific order. Looking at the top of each bearing cap, pull them in a 3, 7,5,4,6,2,1 sequence. {store} The top of each cap should have a number, and an I or E denoting Intake or Exhaust respectively. Set the cams aside on a clean surface. ( A kitchen garbage bag is ideal.)
|
Ex & In Order |
7 |
6 |
1 |
4 |
3 |
5 |
2 |
|
Actual # on Top |
1 |
2 |
3 |
4 |
5 |
6 |
7 |
Remove the exhaust manifold heat shield. Store one and allow the other to slip down near the oxygen sensor. Remove the nuts that connect the exhaust manifold to the head. {store} Leave the manifold in position on the studs. There is a special process we will use to remove it later. Release the hose clamp at the back of the head on the passenger side and pull the hose off of the pipe that comes up from the block.
If you didn't relieve the fuel system either because you forgot, or couldn't start the car, cram a towel under the fuel rail. Label each of the clips before you remove them from the injectors. Using two wrenches, hold the fitting with one wrench as you loosen the bolt on the fuel return pipe towards the front of the vehicle with the other. Remove the bolt that feeds the cold start injector. Use a wrench to remove the pulsation damper at the back of the fuel rail. All these copper gaskets will be replaced if you bought the Toyota Head rebuild kit. If not, you really need to find some replacements for safety sake. Remove the three bolts that hold the fuel rail to the head. The injectors may stay attached to the fuel rail. If so, just make sure you remove all the grommets from the head injector ports. Set this aside in one piece, you can have them cleaned or clean them yourself, but remember their order.
Now the fun part! The lower intake manifold is a major pain. First, beware of the VSV or Vacuum Switch Valve at the front of the engine. This little device is an electric vacuum switch that has one metal tube connection and one plastic connection. The plastic connection breaks EASILY! Its price/size ratio is extravagant as well. (See my Parts page for cost!) Each of these bolts will require the universal joint. Of these bolts, one holds the VSV to the manifold, one holds a metal vacuum bracket, another bolt holds a clip that goes around numerous vacuum lines, and finally one is an electrical ground wire. Remove the vacuum device that connects the EGR cooler to the upper intake manifold. Once you get that off your nearly ready to pull the head!
Intake
Side - Lower Plenum Now the special process mentioned
above. Get under the car, and look at the exhaust manifold. As the manifold
approaches the transmission, you will see a bolt. Both this short bolt and one
above it need to be pulled to take the pressure off of the intake manifold and
allow it to hang. (Don't worry, the exhaust rubber bands will support it for the
little time you have it hanging.) Now, get on the intake side of the car. Using
the 10 mm hex bit on an extension, pull the headbolts in the order below.
|
Exhaust |
3 |
7 |
11 |
13 |
10 |
6 |
2 |
|
Intake |
1 |
5 |
9 |
14 |
12 |
8 |
4 |
This is the sequence which MUST be used to pull the headbolts when standing on the intake side of the engine.
After the headbolts have been pulled in the above order, the exhaust manifold can be pulled off the studs and left to hang temporarily.
Finally, the head is ready to be removed. With a friend, carefully lift the head up off of the engine block in order to prevent yourself from scraping it over the two studs that protrude. Set the head on a surface that will not scrape it. Remove the bolts that attach the EGR cooler to the back of the head. {store} Also, remove any other bolts or nuts that may have been temporarily stored on the head. Pull the plugs. When looking at the head, it was clear that the gasket around cylinder six was shot. The valves were burned and discolored. The plug was also filthy and discolored in cylinder 6. Remember to install at least one of the two bolts that were pulled from the tranny to support the exhaust manifold and avoid stressing the gaskets.
If your rebuilding the head yourself and having it machined, good luck. At this point, I decided to take my head to a professional. At which time, I insisted on a mirror finish and stressed a minimal amount of machining. It is important to tell them your going to install a METAL headgasket. A-1 Superhead in Houston, Texas cleaned, press tested, and resurfaced my original head. They also refaced the valve seats, valves, and resized the guides. Once they did this, they replaced the valve stem oil seals (no more puffs of smoke after sitting overnight) and adjusted the valves by shimming the lash adjusters. I gave them the cams, cam pulleys, and bearing caps. Five days after I gave them the head, the total was $320. I might have complained about the length of time, but UPS was on strike so my ARP bolts were nowhere near Houston.
Refurbished
Head - Mirror Finish While the head was at the machine
shop, I worked on the deck of the block. First, plug all the cylinders with rags
to keep dirt out of them. Plug the oil whole to keep dirt out of it. To remove
the old gasket material I bought a putty knife with a thin blade. In my opinion,
this was the perfect tool because it wasn't sharp enough to scar the surface,
yet was fine enough to force the old gasket material up. After removing the
gasket material, I cleaned the surface with carb cleaner and buffed it with a
towel. I avoided using even fine sand paper or steel wool since the sand could
enter the cylinders. To be honest, I was lucky that the block was in such great
shape. When the head came home I was
amazed! The 1.2 mm HKS metal headgasket had arrived yet the ARP bolts weren't
here. The day the bolts arrived, I put a thin layer of grease on the deck
surface and after placing the gasket down, greased the gasket as well. My
brother and I lifted the head onto the block and aligned the studs carefully
before setting it down. Once the head is on the block, do a little jig!!! Head
Close-up Take each washer from the ARP bolt
kit and apply grease to the flat surface. As you do this, set each washer in
place within the head. After all the washers have been greased and positioned,
grease the threads of each bolts prior to dropping them into the holes of the
head. Now you get to use that 13mm 12-pt deep wall socket you bought for this
job! First, I tightened each bolt with the extension and my fingers. Then, using
a Snap-On torque wrench which I borrowed from the neighborhood mechanic, I
torqued each bolt to 30 ft/lbs. in the correct sequence. Exhaust 12 8 4 2 5 9 13 Intake 14 10 6 1 3 7 11 Repeating the sequence, I torqued
each bolt to 50 ft/lbs. Finally, in a third pass, I torqued each headbolt to 70
ft/lbs. Make sure that the torque wrench snaps/pops in the middle of the
pivoting action. If your torque wrench is snapping/popping when you initially
apply the torque, you may get an inaccurate reading. Typically, this snapping is
caused by the initial friction between the threads of the head and bolts. The
moly lube helps to reduce this friction, but be sure you get each bolts
tightened to an accurate torque. When this is done, do another jig!!! Refurbished
Head Reinstalled The reassembly is quite easy. If
you took the time to properly label everything, reassembly is merely time
consuming because all the parts should be cleaned well prior to installation.
The cam bearing caps should be
tightened in the sequence below to avoid warping them. Run a tiny bed of high
temp sealant under the first caps labeled IN1 and EX1. Make sure the arrows
point forward on each cap. Ex & In Order 7 6 1 4 3 5 2 Actual # on Top 1 2 3 4 5 6 7 Lower Timing Belt Cover Removal and Installation To remove the crank shaft, I used
an impact wrench, but you should be able to borrow a tool from your neighborhood
mechanic. The tool has a chain and long handle. The chain goes around the crank
pulley and locks into the handle, when you apply torque in opposite directions,
the foot of the handle grips the pulley and holds it so the bolt can turn.
You'll need this tool again when you re-install the pulley because it requires
195 ft/lbs. of torque. To remove the pulley from the crankshaft, I rented a
pulley puller from Autozone. Once I got the puller, I had to go buy my own bolts
to fit the holes in the pulley. As the center of the puller extended against the
crankshaft, I noticed it was not long enough to pull the pulley off. In order to
remove the pulley completely, I positioned a large socket under the center of
the puller and against the crankshaft. This part is tricky, I tackled
this PITA before installing the alternator, and if you installed it already, I
suggest you remove it and keep reading. Remove all the smaller bolts that
connect the lower cover to the block. There will be one bolt that goes through
the A.C. compressor bracket. At this point, I took a wire coat hanger and made a
loop through the bracket of the A.C. compressor going up to the engine hook near
the alternator. If you look to the left side of the A.C. compressor, you will
see two large bolts. These bolts hold the A.C. bracket to the engine block. A
third bolt goes through the bracket and then the front of the lower belt cover
into the block. Once you have the compressor supported by the coat hanger,
remove the three bolts. It is very important that you do not allow the
compressor to sag. The aluminum hoses that connect the compressor manifold
to the compressor can break easily and ruin you’re A.C. system. Since
I had just spent $600 on a new one, I was not about to let this happen. With
these bolts removed, the lower front belt cover can be removed. The crankshaft
timing gear can then be removed and the crank shaft oil seal can be replaced.
Tap this seal into place with a large pipe or deep wall socket like one for
removing spindle nuts. Clean the surface within the cover and reinstall the
timing gear. Since its got a woodruff key, it only goes on one way. Timing Belt Replacement and other Preventive Maintenance In order to have a "trouble
free" Supra (yeah right!!!), you should replace the oil pump drive seal
just like you did the crank shaft oil seal prior to installing the timing belt.
To do so, use a screwdriver to hold the gear while you loosen the bolt. Pry the
seal out, and install a new one. Tap the new seal in with a large socket or
piece of pipe. When you replace the idler pulley,
don't tighten it. Make sure the two cam gears are aligned at the top with the
matchmarks on the top rear pulley cover. Put the timing belt around the bottom
of the crankshaft timing gear and up the side of the oil pump drive gear. Pull
the belt taught from the oil pump gear around the intake cam gear. Continue to
hold the belt tight as you go around the exhaust gear and down to the idler
pulley. Once you get the belt around the inside of the idler pulley, attach the
spring. If you kept the belt tight as you went around the cams, you should be
o.k. Tighten the idler bolt, but don't worry about its torque yet. Check the
tension between the oil gear and intake gear is comparable to that between the
exhaust and idler pulley. Re-install the lower timing belt cover and A.C.
bracket. Be careful not to sweat or get any solvent on the timing belt.
Re-install the crankshaft pulley using the woodruff key as your guide.
Re-install the crank shaft bolt and torque to 195 ft/lbs. Turn the crank shaft
two full revolutions and check that the timing marks on the cams are still
aligned with the matchmarks on the cover. If they are correct, torque the idler
pulley and close up the front cover making sure to install a new rubber gasket. Tips to reassembly Be careful not to over-torque any
of the bolts. The primary cause of gasket failure is due to over torque. Also,
make sure the bolts are torqued in a balanced order. Don't start on one end of
the manifold and work to the other. Start in the middle and work to the sides. While you have the intake apart,
and since your waiting for the head to be machined, carefully clean all the
varnish out of the intake manifold and throttle body. A few cans of carb cleaner
are recommended because the pressure helps to rinse away the dirt as you go.
Remember to clean the injectors, fuel rail, and cold start injector. When cleaning the lowest portion
of the intake, I placed a towel on the edge of the block and simply sprayed carb
cleaner into the ports to get all the crap out. Don't make to big a mess since
your doing all this around the wiring harness. When it comes to the wiring
harness, this was designed to fit one way and one way only. Make sure you can
remember where everything went. (The dime sized hose that comes from the lower
portion of the block goes up the inside of the intake manifold and to the
throttle body upon reassembly.) Cooling system If you choose to use a coolant
system additive, just be sure you use distilled water. Even if your using
anti-freeze and water, make sure you use distilled water. The minerals in tap
water will cause plaque build-up in the cooling system. Timing When the CPS is reinstalled, only
tighten the adjustment bolt slightly. After your completely reassembled, and
have changed the oil, use a paper clip to short the diagnostic terminals E1 and
T. Make sure the A.C. is off. Connect a timing light and start the car. If
the car starts, take a few steps back and start humming the theme song to the
movie "The Natural" with Robert Redford. (That's what I
did while dancing a jig!) Using the timing light, shine the gun on the notch
marks in the crankshaft. If your marks are not aligned, loosen the positioning
bolt on the CPS and move it slightly. Retighten the bolt and check the marks
again. If you get 10 degrees below TDC, then pull the jumper wire and
check the timing again. The timing should have moved to 12 degrees below TDC.
If the car didn't start, you didn't take care to mark the position of the CPS
prior to removal. Best of luck, you'll have to guess at the position and keep
trying till it starts. Once it starts, follow the procedure above to make final
adjustments. Now your good to go. Let the car
warm up appropriately. As the car heats up, the grease from the metal headgasket
will burn off from inside the pistons and outside the exhaust manifold.
Although I sold the car in September of 2000, I'd put 47,000 miles on the metal headgasket, ARP bolts, and original block..
Please note, I am not a mechanic. I have never had any official training as a mechanic. If you use the advice below, you do so at your own risk. I will not be held accountable for any communication discrepancies.
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