Table of contents: Examination ↓ Adjustment ↓
Examination
Check the bearings on a warm engine.
1. Remove the cylinder head cover.
2. Remove all spark plugs.
3. Set the piston of the 1st cylinder to TDC of the compression stroke according to the mark on the crankshaft pulley.
The valve lifters of the 1st cylinder must be free (valves are closed), and the 4th cylinder tappets are pressed (valves are open). If this is not the case, turn the crankshaft one revolution and align the mark on the pulley with the pointer again.
4. In this position and the crankshaft check the valve clearances shown in the figure.
To check, insert a blunt between the valve tappet and the back of the camshaft cam. Write down the clearance values that are not within the permissible limits. You will need them when selecting adjusting washers.
Clearances on a warm engine:
- Inlet valves - 0.21-0.49 mm
- Exhaust valves - 0.30-0.58 mm
5. Rotate the crankshaft one revolution (360°) and again align the mark on the pulley with the pointer.
6. Check the valve clearances shown in the figure.
7. If all clearances are normal, reinstall the cylinder head cover and spark plugs.
Adjustment
Adjustment of clearances is performed on a cold engine.
1. Turn the crankshaft to a position where the cam lobe of the valve to be adjusted points upward.
2. Grasp the camshaft with the special tool (A). Before doing this, turn the tappet so that the cutout faces the center of the cylinder head. This will make it easier to remove the washer.
CAUTION: Be careful not to damage the camshaft with tool (A).
3. Turn the tool (A) as shown in the figure to press the pusher down.
4. Install the tool (B) between the tappet and the camshaft to lock the tappet in the depressed position.
CAUTION: Tool (B) should be installed as close to the bearing cap as possible. Be careful not to damage the cam surface with tool (B).
5. Remove the tool (A).
6. Remove the adjusting washer using a small screwdriver and a magnetic pick.
7. Determine the required thickness of the new washer using the formula:
N = R + [M - 0.37 mm] for intake valves or
N = R + [M - 0.40 mm] for exhaust valves,
where R is the thickness of the old washer, N is the thickness of the new washer, M is the measured valve clearance.
Use a micrometer to determine the thickness of the removed washer.
Spare parts include washers of 50 sizes from 2.00 mm to 2.98 mm with a step of 0.02 mm.
See the original on the resource (nissanbook.ru)
Select a new washer with a thickness closest to the calculated value.
8. Install the new washer using a suitable tool. The surface with the stamped numbers should face down.
9. Install the tool (A) as described in points 2 and 3.
10. Remove the tool (B).
11. Remove the tool (A).
12. Check the gap.
After adjusting the clearances on a cold engine, it is necessary to check their size on a warm engine and, if necessary, repeat the adjustment.