Checking valve clearances (XU series engines) (Peugeot 305)

1. Remove the distributor cap with high voltage wires. Unscrew the bolts and remove the valve cover, being careful not to damage the gasket.

2. The engine can be turned either by jacking up one of the front wheels and turning it in 4th or 5th gear, or by using a wrench placed on the crankshaft pulley bolt. The engine will turn over more easily if you remove the spark plugs first.

3. Prepare paper and pencil to record the measured valve clearances.

4. Turn the engine so that the camshaft cam closest to the pulley points vertically upward. Using feeler gauges, measure the gap between the cam base and the tappet (see photo) and write down the obtained value.

5. Repeat the measurements for the remaining 7 valves, turning the engine as necessary so that the desired cam is pointing vertically upward.

6. Calculate the difference between the obtained results and the required valve clearance value (see Specifications). Remember that the valve clearance size for the intake valves is different than for the exhaust valves. Counting from either end of the engine, the valves are arranged in the following sequence: Exhaust - Inlet - Inlet - Exhaust - Exhaust - Inlet - Inlet - Exhaust.

7. If any of the measured gaps is outside the specified limits, it must be adjusted as follows.

8. If all measured clearances are within the specified limits, install the valve cover with a new gasket (if necessary). Please note that there is a copper washer under the bolt on the timing belt side (see photo).