When the oil caps wear out, there is an increased oil consumption and oiled spark plug electrodes
Also a sign of wear is the short-term appearance of blue smoke from the exhaust pipe after starting the engine and when braking the engine after a long movement under load
Oil-removing caps can be replaced without removing the cylinder head
To do this, you need to use a compressor to compress air at a pressure of 0.7-1.0 MPa (7-10 kgf / cm 2) supplied to the candle hole through the device (B) in the figure
At the same time, the piston on the side of the caps being replaced must be in the TDC position, since it is impossible to fix the valves through the spark plug hole on the engines of this car
If there is no compressor, you will have to remove the cylinder head
It is desirable to have a pincer or inertial puller of oil-removing caps
We prepare the car and install it on the lift
Disconnect the negative battery terminal
Unscrewing all spark plugs
We install the piston of the first cylinder in the TDC position, as described in the article "How to install the TDC of the first cylinder of the Mazda 6 engine"
We remove the cylinder head if we perform work with the cylinder head removed How to replace the cover and cylinder head gasket Mazda 6
We remove the pushrods of the cylinder valves, from which we replace the oil-removing caps
It is convenient to use the magnet when removing pushers
We mark the pushers so as not to confuse them when installing
We install a device for removing valve springs on the second cylinder of the engine
We compress the spring of one of the valves with the device
Using tweezers or a magnetized screwdriver, we remove two crackers from the spring plate
Then we remove the device
If we do the work without removing the cylinder head, do not turn off the compressor until the oil cap is replaced and the springs are installed, otherwise the valve will fall into the cylinder
We remove the spring plate and the spring
The removed parts must be installed in their original places
We press the oil-removing cap from the valve guide sleeve
To do this, we install the collet of the inertial puller on the cap and sharply hit the collet sleeve with a striker. Then we sharply hit the handle of the device with a striker, thereby compressing the cap from the sleeve
If there is no inertial puller, we remove the cap with a pincer-type puller or pliers, applying force strictly upwards and without turning the cap so as not to damage the valve guide sleeve
Before installing new oil-removing caps, we recommend removing the springs from them, otherwise the caps can be damaged when they pass through the grooves under the crackers on the valves
If a plastic mounting sleeve is included in the set of new caps, the springs can not be removed. In this case, put the sleeve on the valve stem.
The original oil-removing caps of the intake valves are painted green, the exhaust valves are brown.
Lubricate the inner surface of the oil cap with engine oil and push the cap along the valve stem to the guide sleeve.
Install the mandrel for pressing the cap. Press the cap until it stops with light blows of the striker on the mandrel. In the absence of a special device, you can pick up a cylindrical mandrel of a suitable diameter and press the cap through it with light hammer blows on the mandrel.
As a mandrel, you can use a long head from a set of tools. You need to choose a head with 12 faces and a chamfer inside the hole so that the head contacts the cap along a solid circle.
Remove the guide sleeve from the valve stem or put a spring on the cap if it was removed.
Install the valve spring and plate in the reverse order of removal. Install the crackers using the device so that they enter the grooves of the valve stem
After installing the crackers, hit the end of the valve with a hammer through the metal rod so that the crackers sit in place.
If the crackers installed with a misalignment remain unfixed, when the engine is started, the "decomposed" valve will fall into the cylinder, which will lead to serious engine failure.
Similarly, replace the oil-removing caps of the remaining valves.
Install the removed parts in the reverse order of removal
After installing the camshafts and the timing chain, check and, if necessary, adjust the gaps in the valve actuator