Cylinder Head - Prechamber Cracks

Number: 83-106

Section: 6A (VI)

Date: Nov., 1983
Subject: CYLINDER HEAD PRECHAMBER CRACKS

ON 6.2L DIESEL ENGINES


Model and Year: 1982-83 "C-K-P-G" TRUCKS
TO: ALL CHEVROLET DEALERS


During the service of 6.2L diesel cylinder heads, the observance of hairline cracks may be noted in the prechamber area.

Cracks on the face of the prechamber start at the edge of the fire slot. From the edge, the cracks proceed toward the circular impression of the head gasket bead.

These cracks are a form of stress relief and are completely harmless up to a length of 5 mm (3/16"). cracks longer than this are approaching the head gasket sealing bead and should be replaced with the proper part number.

ACCEPTABLE AND NONACCEPTABLE CRACKS:

The sketch below of a prechamber displays both acceptable and nonacceptable cracks.