#### 1989–92 240SX WITH THE KA24E AND KA24DE ENGINES

NOTE: On the 240SX KA24E engine no routine valve adjustment is necessary or possible these models are equipped with hydraulic lash adjusters, which continually take up excess clearance in the valve train.

NOTE: Datsun/Nissan recommends that valve adjustment on the KA24DE engine should only be done if valve noise increases.

##### KA24DE Engine

1. Run the engine until it reaches normal operating temperature and shut if off.
2. Remove the rocker cover and all spark plugs.

   Fig. 1: Valve adjustment step No. 1 — KA24DE engine

   Fig. 2: Valve adjustment step No. 2 — KA24DE engine

3. Set No. 1 cylinder at TDC on compression stroke. Align pointer with TDC mark on crankshaft pulley. Check that the valve lifters on No. 1 cylinder are loose and valve lifters on No. 4 are tight. If not turn crankshaft one revolution 360°and align as above.
4. Refer to the illustration. Check both No. 1 intake and both No.1 exhaust valves, both No. 2 intake valves and both No. 3 exhaust valves. Using a feeler gauge, measure the clearance between valve lifter and camshaft. Record any valve clearance measurements which are out of specification. Intake Valve clearance (hot) is 0.012–0.015 in. (0.30–0.38mm) and exhaust valve clearance (hot) is 0.013–0.016 in. (0.33–0.40mm).
5. Turn crankshaft one revolution 360°and align mark on crankshaft pulley with pointer. Refer to the illustration. Check both No. 2 exhaust valves, both No. 3 intake valves, both No. 4 intake valves and both No. 4 exhaust valves. Using a feeler gauge, measure the clearance between valve lifter and camshaft. Record any valve clearance measurements which are out of specification. Intake valve clearance (hot) is 0.012–0.015 in. (0.30–0.38mm) and exhaust valve clearance (hot) is 0.013–0.016 in. (0.33–0.40mm).
6. If all valve clearances are within specification, install all related parts as necessary.
7. If adjustment is necessary, adjust valve clearance while engine is cold by removing adjusting shim. Determine replacement adjusting shim size using formula. Using a micrometer determine thickness of removed shim. Calculate thickness of new adjusting shim so valve clearance comes within specified values. R = thickness of removed shim, N = thickness of new shim, M = measured valve clearance.
   - INTAKE: N = R + M
   - EXHAUST: N = R + M
8. Shims are available in 37 sizes (thickness is stamped on the shim — this side is always installed down), select new shims with thickness as close as possible to calculated value.