D21 Hardbody 2WD L4-2389cc 2.4L SOHC (Z24i) (1988)
Crankshaft: Technical Service Bulletins
Engine - 3 Kinds of Noise
Classification:
EM88-014 Section: Engine Mechanical
Reference:
SERVICE ADVISORY TS88-082
Models:
1987-88 Van & Pathfinders 1986.5-88 Trucks (24i engine)
Date:
July 25, 1988
Z24i KNOCKING NOISE
APPLIED MODELS: 1986.5-88 Trucks, 1987-88 Pathfinders & Vans (Z24i engine)
APPLIED VEHICLE PRODUCTION DATES: From September 1, 1986 to December 31, 1987
SERVICE INFORMATION
Some of the applied vehicles manufactured with Z24i engines in the affected range may exhibit one or more of the three different kinds of engine noise
listed below:
Noise Sources/Descriptions
1.
Oil pump pressure relief valve - a metallic rattle noise is heard from the oil pump pressure relief valve, sounding very similar to a heat shield
type rattle. This noise occurs only during engine warm-up
(engine oil temperature:
below 104~F/40~C).
NOTE:
This engine noise occurs only on 1986.5-1987 Truck 2WD models.
2.
Oil gallery plug - a missing or improperly installed oil gallery plug will produce a knocking noise from the lower portion of the engine. This
noise can be heard between 1500-3000 RPM, but is most noticeable around 2000 RPM. The noise will be heard at any engine temperature or
load condition.
3.
Connecting Rod - The large (bearing) end of the connecting rod may produce a bearing type knocking noise from the mid to lower section of
the engine. The noise is loudest between 1500-2000 RPM, during steady throttle or light acceleration.
NOTE:
A countermeasure is now under development to eliminate connecting rod bearing knocking noise. Details will be provided soon
in a Technical Bulletin. Until then, use the diagnostic procedure below when dealing with incident vehicles.
In order to properly diagnose and eliminate the engine noise, it is extremely important to reproduce and identify the particular customer complaint noise.
Use the service procedure on page 2/3 of this Technical Bulletin to diagnose and correct these incidents.
PARTS INFORMATION
PART DESCRIPTION
NUMBER
Plug, oil gallery
12205-21000