Engine Block Heaters - Revised Information

Bulletin No.: T-93-130
File in Group: 16
Number: 50
Corp.Ref.No.: 316104
Date: Aug. 1993

SUBJECT:
INFORMATION ON ENGINE BLOCK HEATERS

MODELS AFFECTED:
ALL 1982-1994 CADILLACS WITH 4.1L, 4.5L, 4.9L V8 ENGINE

Beginning with model year 1987, 4.1L V8 engines received a structural redesign to the engine crankcase which prevents the 1982 through 1986 clamp-on engine block heater from being used. Consequently a revised block heater was released.








As these engines have now been subject to remanufacturing, situations may arise where the revised crankcase is used to produce a 1982 - 1986 application. Figure 1 shows the 1982 - 1986 version, and by comparison with Figure 2 it can be seen that each crankcase requires a specific heater design. When conditions arise where the ribbed crankcase is used in a pre-1987 vehicle with the engine block heater option, a new heater assembly (P/N 1642788) must be purchased.

Both block heater kits are currently available from GMSPO.