944 L4-2681cc 2.7L (1989)
Spark Plug: Technical Service Bulletins
Spark Plug - Recommeded Usage
October 5, 1990
Subject:
Spark Plug Usage
Model
Group
944 S2
2
Part Identifier
Number
2870
9006
ATTENTION: Service Manager/Service Technician
Models Affected:
944 S2 model years 1989, 1990 and 1991
Concern:
944 S2 engines can be equipped with either WR 5 DC or WR 7 DC spark plugs. In general, vehicles delivered
after August 1990 will be equipped with WR 7 DC plugs. The WR 7 DC plug is preferred for use in vehicles
which experience prolonged storage or frequent engine starts followed by short running times since this plug
reaches a self cleaning temperature more quickly than the WR 5 DC plug.
The WR 5 DC plug and the WR 7 DC plug can be used interchangeably but they must not be mixed in an
engine. The WR 7 DC may be replaced by the WR 5 DC anytime (for example at the 30,000 mile maintenance).
Parts Information:
WR 5 DC - Part Number 999 170 179 90 WR 7 DC - Part Number 999 170 158 90