Contents: F8Q Engines 🠛 F9Q Engines 🠛
Note: This step is not included in the maintenance schedule. It should be performed if noise is heard from the valve train or if a loss of power is suspected to be due to incorrect valve clearances. A new valve cover gasket may be required if installed incorrectly.
1. If necessary, release the hoses that pass over the valve cover from their mountings and move them to the side for better access. If the fuel lines are disconnected, plug the open ends to prevent dirt from entering.
2. On F8Q models, remove the mounting bolts and the upper plastic drive belt/right engine mount cover, noting the location of the mounting bolts. On F9Q models, remove the mounting nuts and the sound deadening cover.
3. Loosen the fastening nuts (f8Q engines) or bolts (f9Q engines) and remove the valve cover from the engine. Remove the gasket.
4. When performing the following procedure, the crankshaft must be turned with a wrench on the pulley bolt. To improve access to the bolt, jack up the front right corner of the car and remove the wheel and wheel arch liner (attached with plastic staples).
5. To make it easier to turn the crankshaft, remove the glow plugs (Chapter Engine electrical equipment) or fuel injectors (Chapter Power and exhaust systems).
6. Draw the valve locations on paper, numbering them 1 through 8 from the flywheel (i.e. 1E, 2I, 3E, 4I, 5I, 6E, 7I, 8E; where "E" is the exhaust valve and "I" is the intake valve) (refer to the accompanying illustration).
7. Turn the crankshaft until the valves of cylinder #1 are in the intermediate position - i.e. the exhaust valve will be closing and the intake valve will be opening. The piston of cylinder #4 will be at the top of the compression stroke, and both its valves will be completely closed - and now you can check the clearances of both valves of cylinder #4.
8. Insert the feeler gauge of the correct thickness (refer to Specifications) between the working projection of the cam and the washer on the top of the tappet (refer to the accompanying illustration). If the feeler gauge fits freely or does not fit at all, use feeler gauges of different thicknesses to determine the exact clearance and record it so that you can later calculate the required thickness of the new washer. Note that the clearances for the intake and exhaust valves are different (refer to Specifications).
9. After checking the valve clearances of cylinder #4, turn the crankshaft half a turn so that the valves of cylinder #3 are in an intermediate position, then check the valve clearances of cylinder #2. Also check the clearances of the remaining valves in the sequence shown (refer to the accompanying illustration).
F8Q Engines
Note: A micrometer is required to perform the adjustment.
Adjustment
1a. Where the valve clearance differs from the specified value, it is necessary to replace the adjusting washer, having previously calculated the required thickness. The thickness is indicated on the underside of the washer
1b. But it is better to measure it with a micrometer, because due to wear the washer may be thinner than indicated on it (refer to the illustrations).
2. The required washer thickness is calculated as follows. If the measured gap is less than that specified in Specifications, subtract from the specified in Specifications gap the measured gap, then subtract that difference from the thickness of the existing washer.
For example:
- Example calculation - gap too small
- Measured gap (A) = 0.15 mm
- Required gap (B) = 0.20 mm
- Difference (B-A) = 0.05 mm
- Thickness of installed washer = 3.70 mm
- Required washer thickness = 3.70 - 0.05 = 3.65 mm
3. If the measured gap is greater than that specified in Specifications, subtract the gap indicated in the measurement from the Specifications gap and add the result to the thickness of the existing washer.
For example:
- Example calculation - gap too big
- Measuring gap (A) = 0.50 mm
- desired gap (B) = 0.40 mm
- Difference (A-B) = 0.10 mm
- Thickness of installed washer = 3.45 mm
- Required washer thickness = 3.45 + 0.10 = 3.55 mm
4. The washer can be removed from the tappet without removing the camshaft if you have a special Renault tool (refer to the accompanying illustration).
5. To remove the washer, the tappet must be pressed against the valve spring pressure. Theoretically, this can be done by pushing the lever against the camshaft between the cam lobe surfaces with a suitable screwdriver, pressing the tappet with the adjusting washer down, but this is not recommended by the manufacturer. If this method is used, be very careful not to damage the camshaft, cylinder head or tappet (refer to the accompanying illustration).
6. The working projections of the cams should be directed upward when pressing the pusher, and the pushers themselves should be turned so that their cuts are located perpendicular to the camshaft axis. Install the washer with the thickness marking facing down.
7. If the Renault tool is not available and a suitable replacement cannot be made, then to remove the washers it will be necessary to remove the camshaft as described in Section Removal, inspection and installation of camshaft and tappets.
8. Remove the socket or wrench from the crankshaft pulley bolt.
9. Install the valve cover using a new gasket and tighten the mounting nuts to the specifications given Specifications effort.
10. Install the fuel injectors (as described in Chapter Power and exhaust systems) or glow plugs (Chapter Engine electrical equipment).
11. Install/connect any hoses that were displaced to gain access. If fuel lines were disconnected, reconnect them and then bleed the fuel system as described in Chapter Power and exhaust systems.
12. Install the upper plastic drive belt/right engine mount cover.
F9Q Engines
Note: A micrometer is required to perform the adjustment.
Adjustment
1. Where the valve clearance differs from the specified value, it is necessary to replace the adjusting shim, having first calculated the required thickness. The thickness is indicated on the underside of the shim, but it is better to measure it with a micrometer and then calculate the thickness of the new one as described for F8Q ENGINES above.
2. The adjusting washers are seated in the tappets in such a way that they are very difficult to remove with the camshaft installed. A special Renault tool is required to perform this procedure (refer to the accompanying illustration), but first it will be necessary to remove the intake manifold and exhaust manifold and turbocharger (refer to Chapter Power and exhaust systems).
3. To remove the adjusting shim, rotate the crankshaft in the normal direction until the valve to be adjusted is fully open. Insert the tool through the valve in the cylinder head so that the end of the tool rests on the valve seat (refer to the accompanying illustration).
4. When removing the intake valve washer, rotate the crankshaft a further 180° and reinstall the tool. The tool will hold the valve open, providing enough clearance to remove the washer with a screwdriver. Use the same procedure for the exhaust valves, except that the crankshaft must be rotated 180° against the normal direction of rotation.
5. Before installing the washer, wipe the top of the tappet and make sure all oil is removed from the washer recess in the top of the tappet. Install the washer into the tappet, the protrusion should be located in the tappet recess.
6. If Renault tools are not available, the camshaft must be removed to replace the washers as described in Section 8.
7. Remove the wrench from the crankshaft pulley bolt.
8. Install the valve cover using a new gasket and tighten the mounting bolts to the specified Specifications effort.
9. Install the fuel injectors (as described in Chapter Power and exhaust systems), or glow plugs (Chapter Engine electrical equipment).
10. Install the intake manifold and exhaust manifold and turbocharger as described in Chapter Power and exhaust systems.
11. Install/connect any hoses that were displaced to gain access. If fuel lines were disconnected, reconnect them and then bleed the fuel system as described in Chapter Power and exhaust systems.
12. Install the engine soundproof cover.