To check the serviceability of the hydraulic tappet…
...we press on it with a screwdriver, trying to press the pusher into the socket of the cylinder head (in this case, the corresponding camshaft cam should be facing the pusher with its "back", i.e. do not press on it).
In this case, a serviceable hydraulic tappet will move in the cylinder head socket with significant force, compressing the valve spring. If the hydraulic tappet itself is pressed with little force, it must be replaced.
To do this, remove the camshaft pulley (see Replacing the camshaft seal).
With a "10" head, evenly, in several steps (half a turn per pass) we unscrew two bolts securing each of the five camshaft bearing caps.
We remove the camshaft bearing caps.
First (far right) the lid is different from other lids.
We remove the exhaust camshaft from the cylinder head beds.
If necessary, we similarly dismantle the intake camshaft.
We remove the oil seal from the shaft journal.
We remove the hydraulic tappet from the socket in the cylinder head.
Before installation, place the new hydraulic tappet in a container with clean engine oil and press the plunger pair of the hydraulic tappet several times until air bubbles stop escaping from the hole in its groove.
We install the hydraulic tappet in the reverse order. Other hydraulic tappets are replaced similarly.
Before placing the camshaft in the cylinder head bed, apply a thin layer of engine oil to the bearing journals and cams of the shaft.
Having laid the shaft, we install the shaft bearing caps in accordance with the order of their designation in the cylinder head and the markings on the outer surface of the caps.
The order of designation of the covers in the cylinder head
Lid marking No.1.
Cap marking No.6 (in the photo on the left) and No.9 camshaft bearings.
We tighten the bolts for fastening the shaft bearing caps evenly, moving from cap to cap, in several steps (gradually increasing the tightening torque) tighten the bolts to the required torque (see Tightening torques for critical threaded connections).
We press in the camshaft oil seal (see Replacing the camshaft seal).
We carry out further assembly in reverse order.
After replacing the hydraulic tappet, the engine may operate with increased noise for a short time until the hydraulic tappet is bled.
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