L-Series Wagon 4WD F4-1781cc 1.8L SOHC (Carb) (1987)
Piston: All Technical Service Bulletins
Engine - Diesel Type Knocking Noise
NUMBER 02-56-87
DATE
10-26-87
APPLICABILITY 1987 TURBO VEHICLES (EXCEPT XT)
SUBJECT:
TURBO ENGINE KNOCKING NOISE
If you encounter a customer complaint of a diesel type knocking noise coming from the engine compartment, first check the following VIN and engine
range:
Note:
This Bulletin supercedes and cancels Subaru Service Bulletin number 02-54-87, released 09-28-87.
VIN RANGE
4 DR - 200001 - 234616
Sta. Wagon - 400001 - 465716
3 DR Coupe - 800001 - 812190
ENGINE RANGE
Before Engine Number 405773 (up to March 1987 Production)
Note:
This procedure only applies to vehicles within this range.
1.
Diagnostic Procedure
This procedure is for diagnosing non-destructive engine sound levels on vehicles within the above range. Other engine noises can be diagnosed
using the 1987 Subaru Service Manual Section 2-3, Page 51, "Engine Noise".
^
Set the emergency brake, chock the rear wheels and hold the foot brake.
^
Make sure the engine is at operating temperature and engine idle speed, timing, and cambelt tensioning are correct.
^
Manual transmission vehicles, rev the engine to approximately 1000-1200 RPM. Carefully release/slip the clutch with the transmission 1st
gear. Try not to stall the engine. The diesel type noise should be audible.
^
Automatic transmission vehicles, rev the engine to approximately 1000-1200 RPM with the transmission in "DRIVE". The diesel type noise
should be audible.
^
With the engine idling, and the transmission in "PARK" for automatics and neutral for manual transmissions, remove the #4 injector wire
connector and the noise should diminish.
^
Disconnecting any of the other injector wiring connectors may increase the noise.
FIGURE 1
2.
Repair Procedure