We replace the valve stem seals during cylinder head repair and also when the seals are worn.
A sign of valve stem seal wear is increased oil consumption, as well as blue smoke from the exhaust pipe after starting the engine and during engine braking after prolonged driving under load.
An indirect sign is also oil contamination of the spark plug electrodes.
The following tools are required to carry out the work: 10, 16, 18 sockets, 13 spanner, screwdriver set, Torx E14 socket, TDC locking tool, camshaft locking tool, torque wrench, pliers, tweezers.
Alternatively, an inertia valve stem seal puller can be used.
We prepare the vehicle to carry out the work.
We disconnect the negative battery terminal.
We remove the cylinder head cover (article – Removing the cylinder head cover).
We remove the cylinder head (article – Replacing the cylinder head gasket).
With some experience, the valve stem seals can be replaced without removing the cylinder head.
We remove the rocker arms and hydraulic valve lifters.
We mark the hydraulic lifters and rocker arms according to their positions so as not to mix them up during installation.
We screw the cylinder head cover retaining bolt into the cylinder block hole to install the valve spring compressor.
We set the piston of the cylinder in which we are replacing the seals to TDC (if we carry out the operation without removing the cylinder head).
Compressed air or a rod-shaped support can be used to support the valves.
A tin rod can be used.
We install the spring compressor and compress the spring.
Using tweezers or a magnetised screwdriver, we remove the two collets from the spring retainer.
After that we remove the compressor.
If the force required to move the compressor lever increases noticeably and the collets do not come out of the valve groove, a light hammer blow must be applied to the spring retainer so that the collets are released.
We remove the spring retainer.
We extract the spring.
We fit the collet of the inertia puller onto the valve stem seal and, with two or three sharp blows of the puller striker, achieve locking of the seal in the collet sleeve.
We remove the valve stem seal by pulling the puller strictly upwards.
Fitting the seals
If the set of new seals includes a fitting sleeve, we put it on the valve stem to protect the working edge of the seal from the sharp edges of the collet grooves on the valve stem.
Before fitting new valve stem seals, it is recommended to remove their springs, otherwise the seals may be damaged as they pass through the collet grooves on the valves.
We dip the valve stem seal in engine oil and fit it by hand onto the valve guide.
We fit the puller or drift onto the new valve stem seal.
If no special tool is available, a cylindrical drift of suitable diameter can be selected and the seal pressed on through it with light hammer blows on the drift.
A long socket from the tool kit can be used as a drift.
Choose a 12-point socket with a chamfer inside the hole so that the socket contacts the seal along a continuous circumference.
With light blows of the striker or hammer, we press the seal in as far as it will go.
We put the spring back onto the seal if it was removed.
We install the springs and spring retainers.
Compressing the springs with the compressor, we install the collets so that they seat in the grooves of the valve stem.
After fitting the collets and removing the valve spring compressor, we apply several light hammer blows to the end of the valve stem so that the collets lock in the stem groove.
If the collets fitted at an angle remain unlocked, when the engine is started the «unseated» valve will drop into the cylinder, which will lead to engine failure.
In the same way we replace the valve stem seals on the remaining valves of the cylinder head.
We refit the hydraulic lifters and valve pushrods.
We install all parts in the reverse order.
