Valve clearances (Nissan X-Trail T31)

Checking and adjusting

Examination

If the camshafts or valve related components have been removed or replaced, or if engine operation deviates from normal values over time due to changes in valve clearances, check as follows:

1. Start the engine and warm it up.

2. Turn off the engine.

3. Remove the valve cover. See below.

4. Remove the mudguard from the right fender guard.

5. Measure the valve clearances as follows:

a. Set the piston of cylinder No.1 to TDC in the compression stroke.

• Turn the crankshaft pulley clockwise and align the TDC mark with the timing indicator on the front cover.

• At the same time, make sure that the working projections of the camshafts of the intake and exhaust valves of cylinder No.1 are facing away from each other, as shown in the figure.

• Otherwise, rotate the crankshaft pulley one more revolution (360°) and align them as shown in the figure.

b. Using a feeler gauge, measure the valve clearances between the valve lifters and the camshaft.



Valve clearances. See section below "Technical data and specifications".

• Using the figure, measure the valve clearances using a feeler gauge in the places marked with an "x", as indicated in table No.1 below (in the figure) the places are marked with black arrows.
• Piston of cylinder #1 at TDC in compression stroke

c. Turn the crankshaft pulley one revolution (360°) clockwise, align the TDC mark with the timing indicator on the front cover.

• Using the figure as a guide, measure the valve clearances at the locations marked with an "x" using a feeler gauge, as shown in Table No.2 below (in the figure the places are marked with black arrows).
• Piston of cylinder No.4 at TDC in the compression stroke.

Table No.1

Place of measurement		Cylinder No.1	Cylinder No.2	Cylinder No.3	Cylinder No.4
Piston of cylinder #1 at TDC in compression stroke	Inlet	X	X
	Release	X		X

Table No.2

Place of measurement		Cylinder No.1	Cylinder No.2	Cylinder No.3	Cylinder No.4
Piston of cylinder #4 at TDC in compression stroke	Inlet			X	X
	Release		X		X

6. If the measured value is different from the norm, make adjustments. See below.

Adjustment

Make adjustments based on the selected valve tappet thickness.

1. Remove the camshafts. See above.

2. Remove the valve lifters whose clearances differ from the norm.

3. Using a micrometer, measure the thickness at the center of the removed valve lifters (A).



4. Calculate the thickness of the replacement valve lifter using the following formula.

Calculating the thickness of the valve tappet

t = t1 + (C1 - C2), where:

• t = Thickness of the replacement valve tappet.
• t1 = Thickness of the removed valve tappet.
• C1 = Measured valve clearance.
• C2 = Standard valve clearance.

Inlet 0.28mm

Release 0.30 mm

• The thickness of the new valve tappet (B) can be determined by the marking (A) stamped on the back side (inside the cylinder)

The marking "788" means the thickness is 7.88 mm

Note: Valve tappets are available in 26 thicknesses ranging from 7.88mm to 3.38mm in 0.02mm increments (during manufacturing at the factory).

5. Install the selected valve lifters.

6. Install the camshafts. See above.

7. Turn the crankshaft pulley by hand a few turns.

8. Using standard values, make sure that the valve clearances on a cold engine are within normal limits. See above.

9. Install the remaining components in the reverse order of removal.

10. Warm up the engine and check for any unusual noise or vibration.