North American Turbocoupe Organization

Head Gasket Replacement
andrewjs18 Offline
Head Gasket Replacement
By Pete Dunham

First and foremost, you should get a shop manual (preferably Helm), a supply of plastic storage bags that can be labeled. Put nuts and bolts and small parts in bags and label them, religiously.

Below is a condensed list of things to do. Please refer to a shop manual for complete instructions.

The head can be removed without pulling the turbo.

Set crank to TDC on #1 compression stroke.
Drain coolant, disconnect battery
Remove pipe (or inter cooler) from compressor outlet to throttle body, unbolt EGR pipe from upper intake.

Remove breather from valve cover.
Disconnect wiring connectors at the IAC and TPS at throttle body.
Remove heater hose retaining screw to rocker cover.
Disconnect distributor cap and spark plug wires and remove assy.
Disconnect required vacuum lines (upper intake) and PCV hoses to upper intake.
Remove dipstick.
Remove one bolt holding dipstick tube bracket to wiring harness bracket - upper intake.
Remove upper intake and throttle body (as one piece).
Remove rocker cover bolts.
Remove coolant hose at bottom center of lower intake.
Loosen alternator retaining bolts, remove belt from pulley,remove bracket retaining bolts from head.

Remove upper radiator hose from thermostat housing.
Remove 4 cam belt cover bolts.
Remove cam idler retaining bolts(2) Position idler in the unloaded position and tighten retaining bolts.

Remove cam belt. (the book says remove the lower intake but I think it's easier once the head is out of the car) You don't have to remove it if: it doesn't interfere w/ fuel rail (see below) or head is not going to be machined.

Disconnect wire lead to oil sending unit.
Disconnect harness to fuel injectors.
Unbolt the fuel rail from lower intake If you can move it aside do so, other wise you will
have to disconnect it from the fuel supply and return lines at the back end of the fuel rail,
(it is easier to disconnect them at the lower end, under the car).

Remove timing belt cover, belt, pulley.
Loosen down pipe at turbo elbow (don't remove nuts, loosen).
Disconnect oil supply line at turbo.
Remove exhaust manifold to head bolts .
Remove cylinder head retaining bolts.
Remove cylinder head. Get help for this and remember that the oil supply line to the turbo is still connected to the head at the oil supply manifold, don't damage it.

Clean all gasket surfaces.

VERY IMPORTANT: THOROUGHLY clean out the head bolt holes in the block. This is a must do, leave no oil or crap in the bottom of the holes.

Check head to block surfaces for flatness, have head milled if needed or you will be doing this again soon.

Cylinder head bolt torque is 80 to 90 FT Lbs. Tighten in 3 steps, first to 30 ft lbs, 2nd to 60 ft. lbs and the final step to full torque. Start with the bolts in the center of the head and work your way to each end alternating bolts on each side and each end. Torque sequence is: ( #1 is on the exhaust side of the head and #s 8 & 9 are at the front of the head)

9 5 1 3 7
8 4 2 6 10

I recommend using new head bolts but they can be reused at least once. You can grind the hex head of a couple old ones and then cut a slot in the middle and use these to guide the head on then use a screwdriver to unscrew then.

Lower intake to cylinder head 15-22 ft lbs. Start in the center and work out as for head.

All other torque specs: tight enough

Felpro makes 2 head gaskets that work on the turbo engine.
  • The 8993 is the cheaper of the two and perfectly good for most applications.
  • The 1035 is the better of the two and should be used on high HP application, expensive.

Keep in mind that the head gasket acts like a safety valve, it's better to use the 8993 gasket which will blow before other major internal damage can occur. The 1035 should only be used for high performance application such as racing and those producing over 300 hp.

This might be a good time to do any or all of the following: new timing belt, new idler tensioner, new thermostat, new water pump. Rebuild the head, port the head and manifolds. Install new cam or at least stock valve springs and valve stem seals, valve job. Also remove the coolant fitting from the lower intake and check it and the hole it goes into for blockage (if applicable). New oil pressure sending unit. New coolant hoses everywhere, now is the time to do those hard to get to hoses on the driver's side of the block.

Users browsing this thread:
1 Guest(s)

Theme © iAndrew 2018 - Software MyBB