Method of Using Plastigage

WARNING: This page is about a different car, the 2013 Infiniti FX50. However, it is still accessible from the selected car via links, so may be relevant.

Remove engine oil and dust on crankshaft journal and the surfaces of each bearing completely.
Cut a plastigage slightly shorter than the bearing width, and place it in crankshaft axial direction, avoiding oil holes.
Install main bearing to cylinder block and main bearing cap, and tighten main bearing cap bolts with main bearing cap to the specified torque. Refer to "DISASSEMBLY AND ASSEMBLY " for the tightening procedure.
CAUTION: Never rotate crankshaft.
Remove main bearing cap and bearings, and using the scale on the plastigage bag, measure the plastigage width.
NOTE: The procedure when the measured value exceeds the limit is the same as that described in the "Method by Calculation".

Fig 1: Measuring Plastigage Width Using Scale On Plastigage Bag
Courtesy of NISSAN NORTH AMERICA, INC.