To compensate for the thermal expansion of the valve, a gap is set between the end of the valve stem and the camshaft cam

If the clearance is increased, the valve will not open fully, and if the clearance is reduced, it will not close completely

How to adjust Mazda 6 engine valve clearances

The gap is measured with a feeler gauge on a cold engine (at a temperature of +20º C) between the camshaft cam (the cam must be directed upwards from the tappet) and the valve tappet

The nominal gap for the intake valve is 0.17-0.23 mm, and for the exhaust valve 0.31-0.37 mm

How to adjust Mazda 6 engine valve clearances

The gaps are adjusted by selecting the thickness of the pushers

Spare parts are supplied with sets of pushers of different thicknesses

Regarding the timing drive, the valves located on the right are exhaust, on the left are intake

The work on adjusting the clearances in the valve drive is the same for all engines

Preparing the car for the task

Set the piston of the first cylinder to the TDC position of the compression stroke, as described in the article "How to set the TDC of the first cylinder of the engine Mazda 6"

How to adjust Mazda 6 engine valve clearances

Unscrew all the spark plugs

How to adjust Mazda 6 engine valve clearances

Remove the cylinder head cover, as indicated in the article "replacing cylinder head gaskets"

We measure the gaps between the cams of both camshafts and the valve lifters of the first cylinder with a feeler gauge

Write down the measured clearances

We scroll the crankshaft by the pulley mounting bolt 180º each time, measure and record the valve clearances of the remaining cylinders

Cylinder order 1-3-4-2

It is necessary to replace the tappets of those valves, the gaps in the drive of which differ from the nominal values

After measuring all the gaps, set the piston of the first cylinder to the TDC of the compression stroke

Remove the camshafts

How to adjust Mazda 6 engine valve clearances

We remove the valve tappet from the cylinder head socket, which requires clearance adjustment, and record its thickness (it is indicated on the inner surface of the tappet)

How to adjust Mazda 6 engine valve clearances

The number printed on the inner surface of the valve lifter is the tappet thickness

Only three digits after the decimal point are applied (for example, the number "650" means the thickness of the pusher is 3.650 mm)

We calculate the thickness "H" of the new pusher using the formula (all values ​​in mm)

H = B + A - C, where A is the measured gap; B - the thickness of the old pusher; С - nominal gap

Install the new pusher in place

In the same way, we replace the tappets of all valves that require clearance adjustment

We are installing the camshafts, but we are not installing the timing gear yet

Turn the crankshaft 90º counterclockwise so that all pistons are in the middle position

Scrolling the camshafts for the hexagons made on them, we measure the gaps obtained with a feeler

If the gaps differ from the nominal values, repeat the adjustment

If all the gaps correspond to the nominal values, install the timing gear and all removed parts in the reverse order