Removing the Cylinder Head
Removing the Cylinder Head
John Karr wrote:
I'm also removing the head myself. Egad, my kingdom for the job to ...
..some (hopefully) useful info about removing the cylinder head yourself.
First, be sure to read the excellent online book "The Jaguar XJ6 from bumper to bumper"
by Jim Isbell (another member of the list). This has a very good section on
cylinder-head lifting. You can browse this at http://www.ozemail.com.au/~vaughnb/xj6/index.html
thanks to the superb "HTMLisation" work of Vaughan Bromfield
I removed the head from my '85 4.2 XJ6 last year and wrote a few notes about it
for the list. I've included these below for interest.
Well, I took the cylinder head of my 1985 (Series III) 4.2 XJ6 Sovereign.
Actually, that was about four weeks ago but I've only just got around to writing
- At 105000 miles I have shaving-foam in the breather system (despite the
fact that the oil looks fine - My usual trip is 30 miles to work so the
engine has plenty of time to get nice and hot).
- I also had low compression on number three and need of a good de-coke
plus valve bucket-guide stakedown measures.
- Oil pressure is fine:- 30psi at idle (hot) 60psi at 3000 on (15W-50)
- The Aluminium XK engine cylinder head is clamped down onto the cast iron
block by studs which are anchored right at the bottom of the block in
the crankcase. This means that the studs are "wet" with coolant all
the way up to the cylinder head nuts and consequently the studs get glued
into their holes with all the clag that inevitably builds up.
So unlike many engines where the head comes off easily once you've managed
to get the head/block face split, the jag 6-cyl head has to be fought
all the way!
- I decided to pull the head off using home-made lifting beams straddling
the engine compartment bearing on the inner-wing gutters using threaded
rods and nuts (two on either end of each beam - eight in all).
- I left all three manifolds on (two exhaust and one inlet/fuel-injection)
which gives you more mass to lift but means that you've got something
to get hold of - I used four heavy-duty woven nylon staps going underneath
the manifolds and over the beams. The beams themselves were 3" x 3" timber
(you could use a bit of steel RSJ instead but I didn't have any).
- Actually I tried slightly smaller timbers first but broke them! - that
gives you some idea of the force needed even with nice clean coolant
an no noticable corrosion evident!
- I weighed the head after I got it off and it is about 25kg. With all three
manifolds on that goes up to 50kg - (1 cwt). You need to be reasonably
strong to lift that at arm's length so plan carefully and don't hurt
your back. However, I assure you it CAN be done single-handed!
(I didn't bother taking the bonnet off and lifted the head out sideways).
- The alternative approach I could have used is to unscrew the head studs
first (see Jim Isbell's excellent XJ6 bumper-to-bumper book). If you do
that then the head will come off easily once the joint is split - it's
a cunning idea. It also has the advantage that you don't need to lift the
so high because there are no studs to clear. Mind you;- if you snap off a
stud INSIDE the block then you're in deep shit and are going to need specialist
help of Micheal Neal calibre, (see his technical help section on the web
page). You choose :~)
- Hoorah! the cylinder head is off.
- The exhaust manifolds came off easily. The inlet/fuel-injection manifold required
a little bit of welly. I'll write what I actually DID to the head in another message
when I get round to it - it was fun.
- I am amazed at the condition of the cylinder bores;- you can see the brown laquer
mark where the top piston ring sits but there is practically no discernable ridge in
the bore, you can't even feel it with a thumbnail. Looks like re-boring these engines
at 100000 miles is a waste of time. More like re-bore at 300000 miles with a de-coke
and fresh head gasket every 100000 or so.
..anyway, more waffle on my cylinder head rebuild in a week or two.
....enjoy your Jaguars,
Removing and Replacing the XK (1984) Cylinder Head
The following is a description of the procedure I used
to remove the cylinder head from my 1984 SIII sedan.
This was the first time I had tried this - and I was
scared!!! But I knew I had a lot of good help. Ron
Greim was always ready to help and encourage me. The
fellows at Britalia, Haig and Walter, gave me a lot of
hints. (Additional motivation was provided by
Britalia's price of $1,000 just to pull the head and
put it back, plus another $400 or more for the machine
shop to check the head, valve job, etc.). It took me
about one week to pull the head (had problems with the
pulling tool), 3 days at Sid's machine shop ($425) and
about three days to put it all back together.
I basically used two simple techniques to give me
confidence in doing this. First, every time I removed
something, even a small hose, I wrote it down. Thus
the re-assembly would be "the reverse of the removal".
Secondly, I used little "pricing tags", paper tags
about 1.5 x 2.5 inches with a string loop attached.
So, when ever I took two things apart, like the rear
heater hose from the tube that connects to the water
pump, I put a tag on the hose saying it connected to
the tube from the water pump and a number like 14. I
also put a tag on the tube saying it connected to the
top hose from the heater and the same number, 14.
(Unless it was something very obvious like the ground
wire to the battery).
The head may be pulled with or without both or either
of the exhaust and intake manifolds attached. I
choose to remove both, but, I did not take off the
intake mainfold untill the head was about 4 inches up
on the studs. However on reassembly, I believe it
would have been much easier to bolt on the intake
manifold then put the assembly on the head. If so,
note the 4 electrical connectors hidden by the intake
manifold and reconnect. And the heater tube from the
front to the rear underneath the manifold and the
bracket that holds the cam "Y" oiler tubes to the
head. Reconnect these brackets before letting the
head-manifold all the way down on the head.
I'm not claiming that the way I did it was the best
way, it worked. Also, I believe these notes to be
about 95% correct, but if you find something that
simply looks wrong, it probably is.
So here we go-
Step Number -
- Drink a large mug of ale and sing or hum "God Save
- Disconnect the ground from the battery.
- Remove the front spray shield and drain the
coolant. (2 bolts, 7/16)
- Tighten the hose clamp and put the spray shield
- Disconnect 3 hoses from the air pump. Note the
small hose that runs across the front of the engine.
- Disconnect from the air pump the 2 wire electrical
- Remove the emissions air pump (1 bolt 5/8, 1 bolt
- Remove the U shape bracket that holds the air pump
( 1 bolt)
- On the 2 wing braces disconnect the 2 hoses to the
cruise control bellows, and the 2 hoses to the brake
servo (one of each , each side).
- Remove the 2 wing braces, note the exhaust side
brace is bolted to the coolant tank. (3 bolts, 9/16).
- Remove the long "nut" holding the transmission
stick to the exhaust manifold (1 bolt, 1/2).
- Remove the exhaust heat shield with the air pump
hose assembly (2 bolts 9/16, 1 bolt 7/8).
- Remove the two exhaust manifolds, disconnect from
exhaust pipes first, then from head studs (8 bolts
each manifold, 9/16).
This completes the work on the exhaust side. Now over
to the intake side.
- Remove the air filter canister.
- Disconnect the electrical connector from the air
- Disconnect the accordion hose from the air flow
meter to the engine intake.
- Stuff a small rag into the intake manifold to keep
dirt out of it.
- Remove the air flow meter. There are 3 brackets
holding it, one on top and two below.
- Remove the tube from across the front of the head
that goes to the air pump.
- Remove the ignition coil, bolts and electrical
- Remove the breather housing and rubber dome from
the front of the head, disconnect the tube from the
solenoid. If desired remove the 4 studs. Note the
coarse threads go into the head and that the two
longer studs are on the drivers side.
- Remove the small vacuum hose that goes from the
air pump to a manifold fitting.
- Disconnect small coolant hose from the thermostat
- Remove the large main upper coolant hose.
- Disconnect the coolant bypass hose from the head.
- Disconnect the long hose from water pump to intake
- Remove fuel pump relay ( just as extra safety
- Disconnect fuel supply hose (rear of injector
rail) from injector rail.
- Disconnect short fuel hose that connects pressure
regulator to tube that runs across front of engine.
- Disconnect 3 large electrical connectors at the
back of the intake manifold in a wiring harness, and
the 1 electrical connector at the intake manifold,
low, on side, facing you.
- Disconnect the heater hose from tube at back of
- Disconnect heater hose from same tube at water
- Disconnect the several black ground wires and
other ground wires from the (rear) bolt on the
manifold sensor rail.
- Disconnect the 2 connectors from the solenoid.
- Disconnect the electrical connector going from the
distributor to the amplifier.
- Disconnect the throttle cable and the kickdown
cable from their arms on the manifold.
- Disconnect kickdown cable bracket from manifold (2
- Disconnect the throttle cable from bracket (1
- Disconnect small hose from back of the intake
- Disconnect the sparking plug wires. And maybe
plug the holes with something.
- Disconnect electrical cable across front of
engine, pull it away from theexhaust side over to the
intake side. I could not find the connector for the
green and black wires at the exhaust side, so, I cut
the wires on the exhaust side to be spliced together
later on reassembly.
- Remove the little heat shield from top of head.
- Remove the air injector rail on top of head.
- Remove the oil pipe "Y" at the back of the head (2
bolts, 5/8). Note this tube is held by a small
bracket that is bolted under neath the intake
- Remove the intake and exhaust cam covers.
- Loosen the cam chain tension, take out the 4
cam/sprocket bolts and slide the cam sprockets off of
the cam. Slide the cam sprockets toward the center of
the engine. A small wire at the end of the sprockets
will hold them at the center. (Note we are not doing
the cam notch at 90 degrees routine because the cams
will be taken off the head when the head is checked by
the machine shop).
- Remove 2 nuts from the bottom front of the head (2
- Remove 2 nuts from both sides of the head (4
- Remove the 14 head nuts (14 nuts 3/4). Note how
the engine lifting brackets are fitted.
- Pull the head up about 4 inches.
- Disconnect vacuum hose from distributor.
- Disconnect heater hose from water pump.
- Disconnect the 4 electrical connectors underneath
- Remove the intake manifold, or, pull the head with
the manifold attached.
The cylinder head is now off the block. Drink another
large mug of ale and sing or hum God Save the Queen".
The assembly of the head back onto the block is
the reverse of the removal - with two exceptions. 1)
The number 6 cylinder (front one) must be at TDC
firing, and 2) The cam notches need to be set at 90
|Looking for or selling Jaguar Automobilia? Then use our absolutely free Jaguar Collectibles Exchange!
||Got some pictures you would like to share with other Jag-lovers?
Then try our automated Photo Album and post some images!