Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum - View Single Post - Write-Up: Adjusting the Valve Lash on a '03 350Z

ZMan · 10-11-2011, 02:52 PM

What's going on guys,

Adjusting the valve lash on your engine is one of the most pivotal maintenance procedures that you can perform. It's a good idea to periodically inspect the valve clearance and make necessary adjustments in order to maintain the healthy operation of your engine

With that said, here is the guide to adjusting the valve lash (clearance) on a 350Z. Note that this procedure will most likely also apply to any other vehicle equipped with the VQ35DE engine:

1) Adjust the valve clearance while engine is cold by removing the adjusting shim. The adjusting shim can be removed by using the following procedures:

Turn the crankshaft so the camshaft lobe of the valve to be adjusted is pointed straight up.
Turn the lifter so the notch is pointed towards the center of the cylinder head; this will facilitate the shim removal process.
Using a depressor tool, push down on the lifter and insert a keeper tool on the edge of the lifter to keep the lifter in the depressed position.
Remove the depressor tool and remove the shim with a magnet.

Note: Compressed air can be blown into the hole of the lifter to separate the adjusting shim from the lifter.

2) Determine the replacement adjusting shim size by using the following procedures and formula:

Using a micrometer determine thickness of the removed shim.
Calculate the thickness of a new adjusting shim so valve clearance is within the specified values.
R = thickness of the removed shim.
N = thickness of the new shim.
M = measured valve clearance.
Intake shim determination formula: N = R + (M - 0.0118 in. or 0.30mm)
Exhaust shim determination formula: N = R + (M - 0.0130 in. or 0.33mm)

3) Shims are available in 64 sizes from 0.0913–0.1161 in. (2.32–2.95mm) in steps of 0.004 in. (0.01mm). The thickness is stamped on the shim; this side is always installed facing down. Select new shims with thickness as close as possible to calculated valve and install it in the lifter.

4) Install the new shim onto the lifter.

5) Depress the lifter and remove the keeper tool. Remove the depressor tool and recheck the valve clearance. Repeat this procedure for any other valves requiring adjustment.

6) When all valve adjustments are finished, install the cylinder head cover, spark plugs and the intake manifold collector.

10-11-2011, 02:52 PM	#1
ZMan Join Date: Jul 2011 Location: West Covina, CA Age: 43 Posts: 7 Trader Rating: (0)	Write-Up: Adjusting the Valve Lash on a '03 350Z What's going on guys, Adjusting the valve lash on your engine is one of the most pivotal maintenance procedures that you can perform. It's a good idea to periodically inspect the valve clearance and make necessary adjustments in order to maintain the healthy operation of your engine With that said, here is the guide to adjusting the valve lash (clearance) on a 350Z. Note that this procedure will most likely also apply to any other vehicle equipped with the VQ35DE engine: 1) Adjust the valve clearance while engine is cold by removing the adjusting shim. The adjusting shim can be removed by using the following procedures: Turn the crankshaft so the camshaft lobe of the valve to be adjusted is pointed straight up. Turn the lifter so the notch is pointed towards the center of the cylinder head; this will facilitate the shim removal process. Using a depressor tool, push down on the lifter and insert a keeper tool on the edge of the lifter to keep the lifter in the depressed position. Remove the depressor tool and remove the shim with a magnet. Note: Compressed air can be blown into the hole of the lifter to separate the adjusting shim from the lifter. 2) Determine the replacement adjusting shim size by using the following procedures and formula: Using a micrometer determine thickness of the removed shim. Calculate the thickness of a new adjusting shim so valve clearance is within the specified values. R = thickness of the removed shim. N = thickness of the new shim. M = measured valve clearance. Intake shim determination formula: N = R + (M - 0.0118 in. or 0.30mm) Exhaust shim determination formula: N = R + (M - 0.0130 in. or 0.33mm) 3) Shims are available in 64 sizes from 0.0913–0.1161 in. (2.32–2.95mm) in steps of 0.004 in. (0.01mm). The thickness is stamped on the shim; this side is always installed facing down. Select new shims with thickness as close as possible to calculated valve and install it in the lifter. 4) Install the new shim onto the lifter. 5) Depress the lifter and remove the keeper tool. Remove the depressor tool and recheck the valve clearance. Repeat this procedure for any other valves requiring adjustment. 6) When all valve adjustments are finished, install the cylinder head cover, spark plugs and the intake manifold collector. *diagram courtesy of nissanpartszone.com; all rights reserved