Cylinders, Pistons & Piston Rings Inspection: Pistons

WARNING: This page is about a different car, the 2004 Suzuki Grand Vitara. However, it is still accessible from the selected car via links, so may be relevant.

Inspect piston for faults, cracks or other damages.
Damaged or faulty piston should be replaced.
Piston diameter:
As shown in the figure, piston diameter should be measured at a position 26.5 mm (1.04 in.) ("a") from piston skirt end in the direction perpendicular to piston pin.

Fig 1: Piston Diameter Chart
Courtesy of SUZUKI OF AMERICA CORP.

Fig 2: Measuring Piston Diameter
Courtesy of SUZUKI OF AMERICA CORP.
Piston clearance:
Measure cylinder bore diameter and piston diameter to find their difference which is piston clearance. Piston clearance should be within specification as given below. If it is out of specification, rebore cylinder and use oversize piston.

Piston-to-cylinder clearance: 0.02 - 0.04 mm (0.0008 - 0.0015 in.)

NOTE: Cylinder bore diameter should be measured in 2 places 90 degrees apart.

Fig 3: Measuring Cylinder Bore Diameter & Piston Diameter
Courtesy of SUZUKI OF AMERICA CORP.
Ring groove clearance:
Before checking, piston grooves must be clean, dry and free of carbon.

Fit new piston ring (1) into piston groove, and measure clearance between ring and ring land by using thickness gauge (2). If clearance is out of specification, replace piston.

Ring groove clearance

Top: 0.03 - 0.07 mm (0.0012 - 0.0027 in.)

2nd: 0.02 - 0.06 mm (0.0008 - 0.0023 in.)

Fig 4: Measuring Clearance Between Ring & Ring Land
Courtesy of SUZUKI OF AMERICA CORP.