The recommended maintenance interval for valve clearance adjustment is 12 months/12,000 miles (19,324 km) on 1970-74 models and 12 months/15,000 miles (24,155 km) on 1975-76 models. 1984-86 gasoline engines require valve adjustment at 30,000 miles (48,309 km); diesels require adjustment at 15,000 miles (24,155 km). 1987-89 gasoline engines require inspection and adjustment at 60,000 miles (96,618 km). The clearance may be checked with the engine hot or cold.
Remove the valve cover and crank the engine until number one cylinder is at Top Dead Center (TDC). TDC is the point at which both intake and exhaust valves are fully closed and the piston is on its compression stroke. To find TDC, crank the engine, preferably with a remote starter switch, until the pushrods for both valves on the subject cylinder stop rising (both valves closed). Stop cranking the engine. At this point, it will be easier to find TDC by turning the engine over manually. To accomplish this, remove all of the spark plugs so the compression and resistance to cranking are diminished, and remove the distributor cap so the position of the rotor may be observed. To crank the engine manually, position a socket or closed-end wrench-with a long handle for greater leverage-on the crankshaft damper bolt and turn the crankshaft in the required direction.
At TDC, the piston for the subject cylinder should be at its highest point of travel. Make a visual check or insert a screwdriver through the spark plug hole to make sure that the piston is no longer traveling upward. As an additional check, the distributor rotor should be pointed to the spark plug wire for the subject cylinder at TDC.
Number one cylinder is at TDC when the 0 degree mark on the crankshaft damper aligns with the pointer on the water pump housing. On four-cylinder models, with number one cylinder at TDC, valves (counting from the front) 1, 2, 3, and 5 may be adjusted. On six-cylinder models, with number one cylinder at TDC, valves 1, 2, 3, 6, 7, and 10 may be adjusted.
B20 and B30 Engines
Insert a feeler gauge of the specified thickness between the rocker arm and the valve stem. Adjustment is accomplished by loosening the locknut and turning the adjusting screw and then, without disturbing the adjustment, retightening the locknut.
The remainder of the valves may be adjusted in the following manner. On four-cylinder models, with No. 4 cylinder at TDC, valves (counting form the front) 4, 6, 7, and 8 may be adjusted. On six-cylinder models, with No. 6 cylinder at TDC, valves 4, 5, 8, 9, 11, and 12 may be adjusted.B21, B23, B230 and B234 Engines
See Figures 1, 2, 3, 4, 5 and 6
The B234 16-valve engine has self adjusting valves and hydraulic tappets. They cannot be adjusted during routine maintenance.
Valve clearance is checked every 15,000 miles (24,155 km). If it is necessary to adjust valve clearance, you will need three special tools: first, a valve tappet depressor tool used to push down the tappet sufficiently to remove the adjusting disc (Volvo tool No. 999 5022); second, specially shaped pliers to actually remove and install the valve adjusting disc (Volvo tool No. 999 5026); and third, a set of varying-thickness valve adjusting discs (sometimes called shims) to make the necessary corrections.
The use of the correct special tools or their equivalent is REQUIRED for this procedure.
The procedure for checking, and, if necessary, adjusting the valves is as follows:
- Remove the valve cover. Scribe and number chalk marks on the distributor body indicating each of the four spark plug wire leads in the cap. Remove the distributor cap.
- Crank over the engine with a remote starter switch or with a wrench on the crankshaft pulley center bolt (22mm hex) until the engine is in the firing position for No. 1 cylinder. At this point, the 0° or TDC mark on the crankshaft pulley is aligned with the timing pointer, the rotor is pointing at the No. 1 spark plug wire cap position, and the cam shaft lobes for No. 1 cylinder are pointing at the 10 o'clock and 2 o'clock positions. At this point, the clearance between the rocker arm and valve depressor (tappet) may be checked for the intake and exhaust valves of cylinder No. 1, using a feeler gauge. When checking clearance, the wear limit is 0.010-0.018 in. (0.25-0.45mm) for a cold engine, and 0.012-0.020 in. (0.30-0.50mm) for a hot engine above 176°F (80°C).
- Repeat Step 2 for cylinders 3, 4, and 2 (in that order). Each time, rotate the crankshaft pulley 180° so that the rotor is pointing to the spark plug wire cap position for the cylinder, and the cam lobes are pointing at the 10 and 12 o'clock positions for the valves of that cylinder.
- If any of the valve clearance measurements are outside the wear limit, you will have to remove the old valve adjusting disc and install a new one to bring the clearance within specifications. First, rotate the valve depressors (tappets) until their notches are at a right angle to the engine center line. Attach valve depressor tool 999 5022 to the camshaft and screw down the tool spindle until the depressor (tappet) groove is just above the edge of its bore and still accessible with the special pliers (tool No. 999 5026).
- Remove the valve adjusting disc and measure with a micrometer. Once you've done this much work, the valve clearance should be set to these tolerances: 0.014-0.016 in. (0.35-0.40mm) for a cold engine, and 0.016-0.018 in. (0.40-0.45mm) for a hot one. So, if the measured clearance had been 0.019 in. (0.48mm) and the desired clearance 0.016 in. (0.40mm), for a net difference of 0.003 in. (0.08mm), then the new valve adjusting disc should be 0.003 in. (0.08mm) thicker than the old one to take up the clearance. Valve adjusting discs are available from Volvo in sizes from 0.35mm to 0.45mm (in 0.05mm increments). Always oil the new disc and install it with the marks facing down.
- Remove the valve tappet depressor tool. Rotate the engine a few times and recheck clearance. Install the valve cover with a new gasket. Volvo does not recommend the use of any sealer on its gaskets.
See Figures 7, 8 and 9
Check the valve clearance every 15,000 miles (24,155 km).
In order to gain access to the valve covers, disconnect or remove the following:
- Air conditioning compressor from bracket (do not disconnect refrigerant hoses)
- EGR valve and hoses
- Air conditioning compressor bracket
- Fuel injection control pressure regulator
- Air pump
- Vacuum pump
- Hoses and wires from solenoid valve (California only)
- Using a 36mm hex socket on the crankshaft pulley bolt, rotate the crankshaft to the No. 1 cylinder TDC position. At this point the "O" mark on the timing plate aligns with the crankshaft pulley notch, the distributor rotor is pointing to the No. 1 cylinder spark plug wire cap position, and both valves for No. 1 cylinder have clearance. Be careful, since these engines have two notches: one for No. 1 cylinder TDC and one for No. 6 cylinder TDC. At this position, adjust the intake valves of cylinders No. 1, 2, and 4, and the exhaust valves of cylinders No. 1, 3 and 6. Insert a feeler gauge between the rocker arm and valve stem. Loosen the locknut and turn the adjusting screw in the required direction. Tighten the locknut and recheck the clearance.
- Rotate the crankshaft pulley one full 360° turn to adjust the remaining valves. At this point, the "O" mark will again align with the pulley notch, the rotor is pointing 180° opposite to its former position, and the No. 1 cylinder rockers contact the ramps of the camshaft. At this position (see illustration), adjust the intake valves of cylinders No. 3, 5 and 6, and the exhaust valves of cylinders No. 2, 4, and 5.
- Install the valve covers with new gaskets. Connect all disconnected equipment, taking care that all lines and hoses are attached to the correct ports and are not pinched or kinked. Check also that the compressor bolts are secure and that the belt is properly adjusted for tension.
D24 and D24T Engines
See Figures 10, 11, 12 and 13
The use of the correct special tools or their equivalent is REQUIRED for this procedure.
Always check valve clearances with the cylinder at TDC; rotate the engine 1 / 4 turn past TDC to set the valves.
- Remove the valve cover.
- Use a 17mm socket on the crankshaft pulley. Turn the pulley until the engine is ready to fire on the No. 1 cylinder. The flywheel timing mark should be at zero.
The piston should be at1/4turn past Top Dead Center when setting the valve clearance.
- Line up the valve depressors.
- Turn them so that the notches point slightly upward.
Use tool No. 5196 or equivalent to press the valve depressors. This tool is available from your Volvo dealer.
- The depressor grooves must be above the face so that the disc can be gripped with pliers. These pliers are available from your Volvo dealer under part No. 5195.
- Remove the disc.
- Measure the disc thickness, using a micrometer.
- Observe the following specifications when selecting new discs: Cold engine: 0.02mm (intake), 0.04mm (exhaust). Warm engine: 0.025mm (intake), 0.045mm (exhaust). Discs are available in thicknesses of 0.33-0.43mm, in increments of 0.05mm.
Always use new discs when performing this procedure.
- Oil the new disc and install its marked side down.
- Check the remaining valve clearances.
- Use the following sequence: 1-5-3-6-2-4.
- Recheck the valve clearance for all cylinders.
- Rotate the engine several times, and recheck the clearance.
- Install the valve cover with a new gasket.