Checking the valve guides (Mondeo 1)

In case of repair work on the cylinder head with leaky valves, it is not enough to adjust or replace the valves and valve seats. It is necessary to check the valve guides for wear. Such a check is most necessary on engines with a long service life. Worn valve guides do not ensure the valve fits in the center, which leads to high oil consumption. If the wear of the guides is very large, then the valve guides must be replaced (the work is carried out in the workshop).

Remove the valve.

Clean the valve guide with tube cleaner.



Insert the valve into the guide and check the valve clearance by rocking it back and forth. The valve should not have any noticeable clearance.

Engine	Permissible clearance in mm
	Intake valves	Exhaust valves
Four-cylinder petrol	0.020 - 0.069	0.046 - 0.095
Diesel	0.03 - 0.07	0.04 - 0.08

Measure the gap using improvised means: place a steel square on the cylinder head and valve. Rock the valve in both directions and measure the gap using a template.

Using a suitable reamer, countersink the valve guide to the next upper size limit (workshop work), always starting from the combustion chamber only.

Caution: If you have countersunk the valve guides, you must install valves whose stems correspond to the upper size limit.