GM Service Manual Online
For 1990-2009 cars only

Info - Engine Identification Information

Subject:Engine Identification Information

Models:2003 and Prior Passenger Cars and Trucks
with North American Engines



This bulletin covers the location of the engine identification information for OEM, service, Goodwrench® and remanufactured engines. The OEM information is a paper bar code tag attached to the engine. The Goodwrench® information is on a metal tag attached to the engine.

OEM Identification Information

The engine bar code tag is usually in one of several places. The bar code tag could be on a rocker arm cover, the ends of a cylinder head or on the oil pan or the oil rail area of the engine. The information required from the tag is the 3 position alpha-numeric code which identifies the model of the engine and the series of numbers at the bottom of the tag. The number of digits will vary depending on the engine application. All the numbers will be required to process an engine request. If this is the original engine in the vehicle, the engine information is available in GMVIS. Choose the Vehicle Component selection, the 3 position alpha-numeric code is the Part/Num Broadcast section and the Traceability section is the bar code information that is required. It may be easier to use GMVIS to obtain the necessary information; however, it is only valid for the original engine.

GMVIS Screen


Object Number: 891837  Size: MF

Typical Engine Tag


Object Number: 891814  Size: MF

6 Cylinder Engine Locations

    â€¢ L36 and L67 applications -- Center of the LH rocker arm or LH side of the engine in the oil pan rail area of the engine
    â€¢ LX5 applications -- Front end of the LH rocker cover
    â€¢ L35 and LU3 applications -- Front of the RH cylinder head or right side of the oil pan sump
    â€¢ LA1 and LG8 applications -- Top of the RH rocker arm cover or front of RH oil pan rail
    â€¢ L81 and LA3 applications -- On cam drive cover on the front of the engine
    â€¢ LL8 applications -- Rear of rocker arm cover on the front of oil pan rail on the RH side

V8 Engine Locations

    â€¢ LR4, LM7, LQ4 and LQ9 applications -- Rear of RH cylinder head or RH side of the oil pan
    â€¢ LS1 and LS6 applications -- Rear of LH cylinder head or the front part of LH oil pan rail
    â€¢ L30 and L31 applications -- Rear of RH rocker cover or on the RH side of the oil pan
    â€¢ L46, L37 and LD8 applications -- Front of RH rocker cover or the RH side of oil pan rail

4 Cylinder Engine Locations

    â€¢ L61 applications -- Front of the rocker cover
    â€¢ LN2 and L43 applications -- Top of the rocker arm cover
    â€¢ LD9 applications -- Top of the timing chain cover

Goodwrench® and Remanufactured Engine ID Tags

The tag is made of metal and is approximately 2 in x 1-11/16 in (5.1 cm x 4.3 cm). It is installed on all remanufactured engines and new engines assembled by non-GM suppliers.


Object Number: 891816  Size: LF
(1)Part Number: Eight Numeric Characters Long
(2)Serial Number: Five or Six Numeric Characters Long
(3)Source Code: Four Numeric Characters Long
(4)2.5L (L38/L68/LR8/LN8) Right Side of Block
(5)2.2L (LN2/L43) Left Side
(6)4.0L/4.6L (L47/L37/LD8) Front of Cam Carrier Cover
(7)3.3L/3.8L/4.3L/307cid (LG7/L27/L67/LN3/L35/LF6/LB1/LV2) Right Side Middle of Block
(8)4.3L/5.7L (L99/LT1/LT4) Left Side of Block
(9)7.4L (L19/L29/L21/LP4/LE8) Right Side of Block Under Cylinder Head
(10)2.3L (LD2/LG0/L40) Left Side of Block
(11)2.4L (LD9) Right Side Cam Carrier

Object Number: 891823  Size: LF
(1)Part Number: Eight Numeric Characters Long
(2)Serial Number: Five or Six Numeric Characters Long
(3)Source Code: Four Numeric Characters Long
(4)2.5L (L38/L68/LR8/LN8) Right Side of Block
(5)2.2L (LN2/L43) Left Side
(6)4.0L/4.6L (L47/L37/LD8) Front of Cam Carrier Cover
(7)3.3L/3.8L/4.3L/307cid (LG7/L27/L67/LN3/L35/LF6/LB1/LV2) Right Side Middle of Block
(8)4.3L/5.7L (L99/LT1/LT4) Left Side of Block
(9)7.4L (L19/L29/L21/LP4/LE8) Right Side of Block Under Cylinder Head
(10)2.3L (LD2/LG0/L40) Left Side of Block
(11)2.4L (LD9) Right Side Cam Carrier