Protege L4-1839cc 1.8L DOHC (1990)
Heater Hose: Customer Interest
A/C - Poor Heater Output
U00992
LACK OF HEATER OUTPUT
APPLICABLE MODELS
1990-91 Protege (BP DOHC Engine)
DESCRIPTION
Some 1990-'91 Proteges with the BP DOHC engine may experience insufficient heater output. This may be the result of a machining process where a
piece of casting flash from the blind plug hole on the cylinder head is not completely removed. Figure 1.
Cooling system pressure forces the piece of casting flash into the thermostat housing area where it blocks the heater hose inlet passage.
The result is restricted coolant flow to the heater core causing insufficient heat output.
The machining process has been changed since August 1, 1991.
If the problem exists on a vehicle with a cylinder head produced prior to August 1, 1991, check the heater pipe inlet for a piece of casting flash material.
Follow the Inspection and Repair Procedures shown in this bulletin.
VIN OF PRODUCTION CHANGE
* The revised section indicated by an asterisk. Please replace the original bulletin with this revised bulletin. (See Labor Time)
INSPECTION & REPAIR PROCEDURES
