Coolant - Propylene Glycol Not Approved by Isuzu

BULLETIN NUMBER
SB94-14-005

ISSUE DATE
DECEMBER 1994

GROUP
MISCELLANEOUS

PROPYLENE GLYCOL-BASED ENGINE COOLANT WARNING

AFFECTED VEHICLES

All Isuzu passenger and light duty models.

SERVICE INFORMATION

Some new propylene glycol-based engine coolants, such as Safe Brands' Sierra engine coolant, have recently been marketed in the automotive service industry as "environmentally safe" alternatives to conventional ethylene glycol-based engine coolants.

Propylene glycol-based engine coolants are not approved by Isuzu for use in Isuzu vehicles.

Propylene glycol-based engine coolants do not meet Isuzu engine coolant specifications. Use of propylene glycol-based engine coolants in Isuzu vehicles can cause the following:

^ Reduced heater and defroster performance.

^ Decreased boil protection and freeze protection.

^ Decreased cylinder head heat transfer.

^ Corrosion damage to cooling system metals (if mixed with ethylene glycol-based engine coolant).