GM Service Manual Online
For 1990-2009 cars only

6.6L Diesel Engine


Object Number: 660545  Size: SH
(1)Engine Identification Number Location

Caterpillar® 7.2L


Object Number: 200578  Size: SF

The engine serial number for the Caterpillar® 3126 diesel engine is on a metal plate on the upper left rear corner of the engine block.

8.1L Engine


Object Number: 661671  Size: SH
(1)Engine Identification Number Location

Engine VIN Derivative


Object Number: 290685  Size: SH
(1)Division Identifier
(2)Model Year
(3)Assembly Plant
(4)Sequence Number

The engine unit number or date code is stamped on the engine block.

Engines are stamped with an 9-digit engine identification number.

DURAMAX™ DIESEL, 7800 Series

The engine serial number is located on the front right side corner of the engine block.