Diesel Cylinder Heads - Normal Cracking
Bulletin 84-6-20Date March '84
Ref. No. 84-122-6
SUBJECT: DIESEL ENGINE WITH CRACKED CYLINDER HEADS
MODELS AFFECTED: ALL EQUIPPED WITH DIESEL ENGINES
We continue to hear about diesel cylinder heads being replaced because of cracks between the intake and exhaust valve seats. Cracks in the seat area are normal for both 5.7L and 4.3L diesel as well as some other diesel engines produced by other manufacturers. Many cylinder heads that have been returned to Buick have been examined and the cracks are superficial. The coolant is approximately 5/8" away from the crack and therefore will not result in a loss of coolant or compression.