Piston rings — check

1. Check piston rings for excessive wear, damage or breaks and replace with new ones if found to be defective. If the piston has been replaced, the piston rings must also be replaced.

2. Check piston ring height clearance (pic. 2.37). If the value is out of range, replace the piston ring, piston, or both.



Normal Clearance:

• Top compression ring - 0.03-0.06 mm.
• Lower compression ring - 0.02-0.06 mm.
• Permissible value: 0.1 mm.

3. Install the piston ring in the cylinder bore.

4. Press the piston ring with the piston so that it is at right angles to the bore of the cylinder (pic. 2.38). Then measure the piston ring gap with a gauge.



If the clearance is too large, replace the piston ring.
Normal value:

• Upper compression ring 12-valve engines - 0.20-0.35 mm,
• The lower compression ring of 12-valve engines is 0.20-0.35 mm.
• Compressor rings for 8-valve engines G13B, 4G13, 4G15 - 0.20-0.40 mm.
• Oil scraper ring - 0.20-0.70 mm.

Permissible value:

• Compression rings - 0.8 mm.
• Oil scraper ring -1.0 mm.