Exhaust System/Engine Controls - Idle Boom/Rough Idle
Article No.04-8-6
05/03/04
^ ENGINE - BOOM/VIBRATION AT 1800-2200 RPM -
ROUGH IDLE - 2.3L ENGINE
^ VIBRATION - BOOM/VIBRATION AT 1800-2200
RPM - ROUGH IDLE - 2.3L ENGINE
FORD:
2001-2004 RANGER
ISSUE
Some 2001-2004 Ranger vehicles equipped with a 2.3L engine may exhibit a condition of either:
^ Boom Or Vibration With RPM Between 1800-2200, Or
^ Rough Idle
Either condition may be due to exhaust system tuning, and to the powertrain and exhaust not being neutralized.
NOTE
IT IS NORMAL FOR A FOUR (4) CYLINDER ENGINE TO HAVE A NOMINAL LEVEL OF POWERTRAIN BOOM, VIBRATION OR ROUGH IDLE. COMPARE THE CONCERN VEHICLE TO A SIMILAR RANGER TO DETERMINE IF THE LEVEL OF BOOM, VIBRATION OR ROUGH IDLE IS NORMAL BEFORE PROCEEDING WITH ANY REPAIRS.
ACTION
Refer to the following Service Procedure.
SERVICE PROCEDURE
1. First road test vehicle to determine the condition, RPM BOOM/VIBRATION or ROUGH IDLE.
1800-2200 RPM BOOM/VIBRATION REPAIR PROCEDURE
For 2001-2003 Ranger, install a new muffler and exhaust pipe assembly, and new front and rear hangers. Leave the catalytic converter pipe to muffler and exhaust pipe connection loose. Torque the front and rear hanger nuts to 23 N.m (17 lb-ft). Then proceed to NEUTRALIZE POWERTRAIN AND EXHAUST SYSTEM for either AUTOMATIC or MANUAL transmission. For 2004 Ranger, DO NOT change the muffler and exhaust pipe. Loosen the nuts at the flange between the catalytic converter pipe and muffler and exhaust pipe. Then proceed to NEUTRALIZE POWERTRAIN AND EXHAUST SYSTEM for either AUTOMATIC or MANUAL transmission.
ROUGH IDLE REPAIR PROCEDURE
For 2001-2004 Ranger, DO NOT change the muffler and exhaust pipe. Loosen the nuts at the flange between the catalytic converter pipe and muffler and exhaust pipe. Then proceed to
NEUTRALIZE POWERTRAIN AND EXHAUST SYSTEM for either AUTOMATIC or MANUAL transmission.
NOTE
THE NEUTRALIZE POWERTRAIN AND EXHAUST SYSTEM PROCEDURES MUST BE FOLLOWED EXACTLY IN THE SEQUENCE DESCRIBED.
NEUTRALIZE POWERTRAIN AND EXHAUST SYSTEM (AUTOMATIC TRANSMISSION)
1. For 2003 automatic transmission equipped vehicles with a ROUGH IDLE only, reprogram the PCM to the latest level using WDS release 25.6 or later.
2. Loosen but do not remove:
^ Left engine support insulator nuts (Figure 1).
^ Right engine support insulator nuts (Figure 1).
^ Transmission extension housing to cross member mount nuts (Figure 2).
^ Exhaust manifold to catalytic converter pipe nuts.
3. Start the engine.
4. Apply the park brake and the service brake.
5. Place the transmission in drive.
6. Slightly raise the engine RPM until the powertrain moves/shifts under torque.
7. Place the transmission in Reverse.
8. Slightly raise the engine RPM until the powertrain moves/shifts under torque.
9. Repeat Steps 5-8.
10. Place the transmission in Park and turn off the engine.
11. Tighten the powertrain and exhaust system attachments in the following sequence:
a. Left engine insulator nuts torque to 102 N.m (75 lb-ft) (Figure 1).
b. Right engine insulator nuts torque to 102 N.m (75 lb-ft) (Figure 1).
c. Transmission extension housing to cross member mount nuts torque to 99 N.m (73 lb-ft) (Figure 2).
d. Exhaust manifold to catalytic converter pipe nuts (support the catalytic converter and pipe in a neutral position while tightening) torque to 40 N.m (30 lb-ft).
e. Catalytic converter pipe to muffler and exhaust pipe nuts (do not support the exhaust system while tightening) torque to 40 N.m (30 lb-ft).
f. Check the powertrain and exhaust to ensure there are no points grounded out to the body. Inspect for other possible ground-outs to the dash-panel, like wire harness, hoses, etc.
12. Check and if necessary, reposition the exhaust damper in front of the catalytic converter to muffler and exhaust pipe connection. The damper should be located 114 mm (4.5") forward of the catalytic converter flange (Figure 3) and at an angle of 54 degrees from horizontal or between 10:30 and 11:00 o'clock when viewed from the rear to the front of the vehicle (Figure 4). Torque the attaching nuts to 47.5 N.m (35 lb-ft).
13. Start the engine and check for exhaust system leaks.
14. Road test the vehicle to confirm the condition is improved.
NEUTRALIZE POWERTRAIN AND EXHAUST SYSTEM (MANUAL TRANSMISSION)
1. Loosen but do not remove:
^ Left engine support insulator nuts (Figure 1).
^ Right engine support insulator nuts (Figure 1).
^ Transmission extension housing to cross member mount nuts (Figure 5).
^ Exhaust manifold to catalytic converter pipe nuts.
2. Start the engine.
3. Apply the park brake.
4. Place the transmission in 1st gear.
5. Slightly raise the engine RPM and slowly let out the clutch until the Powertrain moves/shifts under torque.
6. Place the transmission in Reverse.
7. Slightly raise the engine RPM and slowly let out the clutch until the Powertrain moves/shifts under torque.
8. Repeat Steps 5-7.
9. Place the transmission in Neutral and turn off the engine.
10. Tighten the powertrain and exhaust system attachments in the following sequence:
a. Left engine insulator nuts torque to 102 N.m (75 lb-ft) (Figure 1).
b. Right engine insulator nuts torque to 102 N.m (75 lb-ft) (Figure 1).
c. Transmission extension housing to cross member mount nuts torque to 98 N~m (72 lb-ft) (Figure 5).
d. Exhaust Manifold to catalytic converter pipe nuts (support the catalytic converter and pipe in a neutral position while tightening) torque to 40 N.m (30 lb-ft).
e. Catalytic converter pipe to muffler and exhaust pipe nuts (do not support the exhaust pipe while tightening) torque to 40 N.m (30 lb-ft).
f. Check the Powertrain and exhaust to ensure there are no points grounded out to the body. Inspect for other possible ground-outs to the dash-panel, like wire harness, hoses, etc.
11. Start the engine and check for exhaust system leaks.
12. Road test the vehicle to confirm the condition is improved.
Labor Operation Claiming Chart
Obtain an Authorized Modifications Decal (FPS 8262 - obtainable through DOES II, 25/pkg) and list the date, dealer number, and summary of modifications performed. Select a prominent place adjacent to the Vehicle Emission Control Information Decal suitable for installing the Authorized Modifications Decal. Clean the area, install the decal, and cover it with a clear plastic decal shield.
Parts Block
OTHER APPLICABLE ARTICLES: NONE
WARRANTY STATUS: Eligible Under Provisions Of New Vehicle Limited Warranty Coverage
DEALER CODING
CONDITION
BASIC PART NO. CODE
5K214 42
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