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JOHN aka Eauto
JOHN aka Eauto, The Car Guy
Category: Nissan
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1998 nissan frontier: 4cyl..replaced timing chain..adjust

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1998 nissan frontier 4cyl. replaced timing chain, but know values are making a lot of noise, can you adjust or what.

Check valve clearance while engine is warm but not running.

  1. Remove rocker cover and all spark plugs
  2. Set No. 1 cylinder at TDC on its compression stroke
    • Align pointer with TDC mark on crankshaft pulley.
    • Check that 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.

  1. Check only those valves shown in the figure.
Using a feeler gauge, measure clearance between valve lifter and camshaft. Record any valve clearance measurements which are out of specification. They will be used later to determine the required replacement adjusting shim. Valve clearance (Hot): Intake: 0.31 - 0.39 mm (0.012 - 0.015 inch) Exhaust: 0.33 - 0.41 mm (0.013 - 0.016 inch)

  1. Turn crankshaft one revolution (360°) and align mark on crankshaft pulley with pointer.
  2. Check those valves shown in the figure.
    • Use the same procedure as mentioned in step 4.
  1. If all valve clearances are within specification, install the following parts.

Adjust valve clearance while engine is cold.

  1. Turn crankshaft to position cam lobe on camshaft of valve that must be adjusted upward.
  2. Place Tool (A) around camshaft as shown in figure

Rotate Tool (A) so that lifter is pushed down. Before placing Tool (A), rotate notch toward center of cylinder head (See image), to simplify shim removal later. CAUTION: Be careful not to damage cam surface with Tool (A)
  1. Place Tool (B) between camshaft and the edge of the valve lifter to retain valve lifter. CAUTION:
    • Tool (B) must be placed as close to camshaft bracket as possible.
    • Be careful not to damage cam surface with Tool (B).
  1. Remove Tool (A).

Remove adjusting shim using a small screwdriver and a magnetic finger

  1. Determine replacement adjusting shim size as follows.

    1. Using a micrometer determine thickness of removed shim.
    2. 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 & Exhaust: N = R + [M - 0.37 mm (0.0146 inch)]

    3. Shims are available in thicknesses from 1.96 mm (0.0772 inch) to 2.68 mm (0.1055 in), in steps of 0.02 mm (0.0008 inch).

      1. Select new shim with thickness as close as possible to calculated value.
      nstall new shim using a suitable tool.
      • Install with the surface on which the thickness is stamped facing down.
    4. Place Tool (A) as mentioned in steps 2 and 3.
    5. Remove Tool (B).
    6. Remove Tool (A).
    7. Recheck valve clearance.


    Customer: replied 7 years ago.

    I am not a mechanic, a mechanic put my timing chain in. the front top is where all the motor noise is coming from and someone told me it is the valves. are you telling me that I need to take it back and get this done. thanks. The motor has 195,000 miles on it.

    Just the timing chain was making noise when I took it to the shop. It runs fine but a lot of tapping. thanks again

    yea i would start by having a valve adjustment done
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