Crankcase Ventilation System Inspection/Description
A crankcase ventilation system is used in order to provide a more complete scavenging of crankcase vapors. The air cleaner supplies fresh air through a filter to the crankcase. The crankcase mixes the fresh air with blow-by gases. This mixture then passes through a pipe located in the intake manifold.
The crankcase ventilation system has no serviceable components, so no maintenance of the system is required.
Test Description
The number(s) below refer to the step number(s) on the diagnostic table.
- 2: The noise may not be engine related. This step is to verify that the engine is making the noise. If the engine is not making the noise do not proceed further with this table.
- 3: The noise may be an internal engine noise. Removing the drive belt and operating the engine for a brief period will verify the noise is related to the drive belt. When removing the drive belt(s) the water pump may not be operating and the engine may overheat. Also DTCs may set when the engine is operating with the drive belt removed.
- 4: Inspect all drive belt pulleys for pilling. Pilling is the small balls or pills or it may be strings in the drive belt grooves from the accumulation of rubber dust.
- 6: Misalignment of the pulleys may be caused from improper mounting of the accessory drive component, incorrect installation of the accessory drive component pulley, or the pulley bent inward or outward from a previous repair. Test for a misaligned pulley using a straight edge in the pulley grooves across two or three pulleys. If a misaligned pulley is found refer to that accessory drive component for the proper installation procedure for that pulley.
- 10: Inspecting of the fasteners can eliminate the possibility that a wrong bolt, nut, spacer, or washer was installed.
- 12: Inspecting the pulleys for being bent should include inspecting for a dent or other damage to the pulleys that would prevent the drive belt from not seating properly in all of the pulley grooves or on the smooth surface of a pulley when the back side of the belt is used to drive the pulley.
- 14: Replacing the drive belt when it is not damaged or there is not excessive pilling will only be a temporary repair.
| Step | Action | Yes | No |
|---|---|---|---|
| NOTE: Refer to Belt Dressing Notice in Cautions and Notices. DEFINITION: The following items are indications of chirping: A high pitched noise that is heard once per revolution of the drive belt or a pulley. It usually occurs on cold damp mornings and will subside once vehicle reached normal operating temp. | |||
| 1 | Did you review the Drive Belt Symptom operation and perform the necessary inspections? | Go to Step 2 | Go to Symptoms - Engine Mechanical |
| 2 | Verify that there is a chirping noise. Does the engine make the chirping noise? | Go to Step 3 | Go to Diagnostic Aids |
| 3 | Remove the drive belt. Refer to Drive Belt Replacement . Operate the engine for no longer than 30 to 40 seconds. Does the chirping noise still exist? | Go to Engine Noise on Start-Up, but Only Lasting a Few Seconds | Go to Step 4 |
| 4 | Inspect for severe pilling exceeding 1/3 of the belt groove depth. Does the belt grooves have pilling? | Go to Step 5 | Go to Step 6 |
| 5 | Clean the drive belt pulleys with a suitable wire brush. Did you complete the repair? | Go to Step 15 | Go to Step 6 |
| 6 | Inspect for misalignment of the pulleys. Are any of the pulleys misaligned? | Go to Step 7 | Go to Step 8 |
| 7 | Replace or repair any misaligned pulleys. Did you complete the repair? | Go to Step 15 | Go to Step 8 |
| 8 | Inspect for bent or cracked brackets. Did you find any bent or cracked brackets? | Go to Step 9 | Go to Step 10 |
| 9 | Replace any bent or cracked brackets. Did you complete the repair? | Go to Step 15 | Go to Step 10 |
| 10 | Inspect for improper, loose or missing fasteners. Did you find the condition? | Go to Step 11 | Go to Step 12 |
| 11 | Tighten any loose fasteners. Replace any improper or missing fasteners. Refer to Fastener Tightening Specifications . Did you complete the repair? | Go to Step 15 | Go to Step 12 |
| 12 | Inspect for a bent pulley. Did you find the condition? | Go to Step 13 | Go to Step 14 |
| 13 | Replace the bent pulley. Did you complete the repair? | Go to Step 15 | Go to Step 14 |
| 14 | Replace the drive belt. Refer to Drive Belt Replacement Did you complete the repair? | Go to Step 15 | Go to Diagnostic Aids |
| 15 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | Go to Step 3 |
| NOTE |
|---|
| Refer to Belt Dressing Notice in Cautions and Notices. |
Drive Belt Chirping Diagnosis
The number(s) below refer to the step number(s) on the diagnostic table.
- 2: The noise may not be engine related. This step is to verify that the engine is making the noise. If the engine is not making the noise do not proceed further with this table
- 3: The noise may be an internal engine noise. Removing the drive belt and operating the engine for a brief period will verify the squeal noise is the drive belt(s) or an accessory drive component. When removing the drive belt the water pump may not be operating and the engine may overheat. Also DTCs may set when the engine is operating with the drive belt removed.
- 4: This test is to verify that an accessory drive component does not have a seized bearing. With the belt remove test the bearings in the accessory drive components for turning smoothly. Also test the accessory drive components with the engine operating by varying the load on the components to verify that the components operate properly.
- 5: This test is to verify that the drive belt tensioner operates properly. If the drive belt tensioner is not operating properly, proper belt tension may not be achieved to keep the drive belt from slipping which could cause a squeal noise.
- 6: This test is to verify that the drive belt(s) is not too long, which would prevent the drive belt tensioner from working properly. Also if an incorrect length drive belt was installed, it may not be routed properly and may be turning an accessory drive component in the wrong direction.
- 7: Misalignment of the pulleys may be caused from improper mounting of the accessory drive component, incorrect installation of the accessory drive component pulley, or the pulley bent inward or outward from a previous repair. Test for a misaligned pulley using a straight edge in the pulley grooves across two or three pulleys. If a misaligned pulley is found refer to that accessory drive component for the proper installation procedure for that pulley.
- 8: This test is to verify that the pulleys are the correct diameter or width. Using a known good vehicle compare the pulley sizes.
| Step | Action | Yes | No |
|---|---|---|---|
| NOTE: Refer to Belt Dressing Notice in Cautions and Notices. DEFINITION: The following items are indications of drive belt squeal: A loud screeching noise that is caused by a slipping drive belt (this is unusual for a drive belt with multiple ribs) The noise occurs when a heavy load is applied to the drive belt, such as an air conditioning compressor engagement snapping the throttle, or slipping on a seized pulley or a faulty accessory drive component. | |||
| 1 | Did you review the Drive Belt Symptom operation and perform the necessary inspections? | Go to Step 2 | Go to Symptoms - Engine Mechanical |
| 2 | Verify that there is a squeal noise. Does the engine make the squeal noise? | Go to Step 3 | Go to Diagnostic Aids |
| 3 | Remove the drive belt(s). Refer to Drive Belt Replacement Operate the engine for no longer than 30 to 40 seconds. Does the noise still exist? | Go to Engine Noise on Start-Up, but Only Lasting a Few Seconds | Go to Step 4 |
| 4 | Inspect for an accessory drive component seized bearing or a faulty accessory drive component. Did you find and correct the condition? | Go to Step 9 | Go to Step 5 |
| 5 | Test the drive belt tensioner for proper operation. Refer to Drive Belt Tensioner Diagnosis Did you find and correct the condition? | Go to Step 9 | Go to Step 6 |
| 6 | Inspect for the correct drive belt length. Refer to Drive Belt Replacement Did you find and correct the condition? | Go to Step 9 | Go to Step 7 |
| 7 | Inspect for misalignment of a pulley. Did you find and correct the condition? | Go to Step 9 | Go to Step 8 |
| 8 | Inspect for the correct pulley size. Did you find and correct the condition? | Go to Step 9 | Go to Drive Belt Idler Pulley Replacement |
| 9 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | Go to Step 3 |
| NOTE |
|---|
| Refer to Belt Dressing Notice in Cautions and Notices. |
Drive Belt Squeal Diagnosis
The number(s) below refer to the step number(s) on the diagnostic table.
- 3: This test is to verify that the noise is being caused by the drive belt(s) or the accessory drive components. When removing the drive belt the water pump may not be operating and the engine may overheat. Also DTCs may set when the engine is operating with the drive belt removed.
- 4: The inspection should include checking the drive belt tensioner and the drive belt idler pulley bearings. The drive belt(s) may have to be installed and the accessory drive components operated separately by varying their loads. Refer to the suspected accessory drive component for the proper inspection and replacement procedure.
| Step | Action | Yes | No |
|---|---|---|---|
| NOTE: Refer to Belt Dressing Notice in Cautions and Notices. DEFINITION: A high pitched continuous noise that may be caused by an accessory drive component failed bearing. | |||
| 1 | Did you review the Drive Belt Symptom operation and perform the necessary inspections? | Go to Step 2 | Go to Symptoms - Engine Mechanical |
| 2 | Verify that there is a whine noise. Does the engine make the whine noise? | Go to Step 3 | Go to Diagnostic Aids |
| 3 | Remove the drive belt(s). Refer to Drive Belt Replacement . Operate the engine for no longer than 30 to 40 seconds. Does the whine noise still exist? | Go to Engine Noise on Start-Up, but Only Lasting a Few Seconds | Go to Step 4 |
| 4 | Inspect for a failed accessory drive component bearing. Did you find and repair the condition? | Go to Step 5 | Go to Diagnostic Aids |
| 5 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | |
| NOTE |
|---|
| Refer to Belt Dressing Notice in Cautions and Notices. |
Drive Belt Whine Diagnosis
The number(s) below refer to the step number(s) on the diagnostic table.
- 2: This test is to verify that the symptom is present during diagnosing. Other vehicle components may cause a similar symptom.
- 3: This test is to verify that the drive belt(s) is causing the rumbling noise. Rumbling noise may be confused with an internal engine noise due to the similarity in the description. Remove only one drive belt at a time if the vehicle has multiple drive belts. When removing the drive belt the water pump may not be operating and the engine may overheat. Also DTCs may set when the engine is operating with the drive belt removed.
- 4: Inspecting the drive belt(s) is to ensure that it is not causing a the noise. Small cracks across the ribs of the drive belt will not cause the noise. Belt separation is identified by the plys of the belt separating and may be seen at the edge of the belt our felt as a lump in the belt.
- 5: Small amounts of pilling is normal condition and acceptable. When the pilling is severe the drive belt does not have a smooth surface for proper operation.
| Step | Action | Yes | No |
|---|---|---|---|
| NOTE: Refer to Belt Dressing Notice in Cautions and Notices. DEFINITION: A low pitch tapping, knocking, or thumping noise heard at or just above idle. Heard once per revolution of the drive belt or a pulley. Rumbling may be caused from: Pilling, the accumulation of rubber dust that forms small balls (pills) or strings in the drive belt pulley groove The separation of the drive belt A damaged drive belt | |||
| 1 | Did you review the Drive Belt Symptom operation and perform the necessary inspections? | Go to Step 2 | Go to Symptoms - Engine Mechanical |
| 2 | Verify that there is a rumbling noise. Does the engine make the rumbling noise? | Go to Step 3 | Go to Diagnostic Aids |
| 3 | Remove the drive belt(s). Refer to Drive Belt Replacement Operate the engine for no longer than 30 to 40 seconds. Does the rumbling noise still exist? | Go to Engine Noise on Start-Up, but Only Lasting a Few Seconds | Go to Step 4 |
| 4 | Inspect the drive belt(s) for damage, separation, or sections of missing ribs. Did you find any of these conditions? | Go to Step 7 | Go to Step 5 |
| 5 | Inspect for severe pilling of more than 1/3 of the drive belt pulley grooves. Did you find severe pilling? | Go to Step 6 | Go to Step 7 |
| 6 | Clean the drive belt pulleys using a suitable wire brush. Reinstall the drive belt. Refer to Drive Belt Replacement Did you complete the repair? | Go to Step 8 | Go to Step 7 |
| 7 | Install a new drive belt. Refer to Drive Belt Replacement Did you complete the replacement? | Go to Step 8 | |
| 8 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | Go to Diagnostic Aids |
| NOTE |
|---|
| Refer to Belt Dressing Notice in Cautions and Notices. |
Drive Belt Rumbling Diagnosis
The number(s) below refer to the step number(s) on the diagnostic table.
- 2: This test is to verify that the symptom is present during diagnosing. Other vehicle components may cause a similar symptom such as the exhaust system, or the drivetrain.
- 3: This test is to verify that the drive belt(s) or accessory drive components may be causing the vibration. When removing the drive belt the water pump may not be operating and the engine may overheat. Also DTCs may set when the engine is operating with the drive belt removed.
- 4: The drive belt(s) may cause a vibration. While the drive belt(s) is removed this is the best time to inspect the condition of the belt.
- 6: Inspecting of the fasteners can eliminate the possibility that a wrong bolt, nut, spacer, or washer was installed.
- 8: This step should only be performed if the fan is driven by the drive belt. Inspect the engine cooling fan for bent, twisted, loose, or cracked blades. Inspect the fan clutch for smoothness, ease of turning. Inspect for a bent fan shaft or bent mounting flange.
- 9: This step should only be performed if the water pump is driven by the drive belt. Inspect the water pump shaft for being bent. Also inspect the water pump bearings for smoothness and excessive play. Compare the water pump with a known good water pump.
- 10: Accessory drive component brackets that are bent, cracked, or loose may put extra strain on that accessory component causing it to vibrate.
| Step | Action | Yes | No |
|---|---|---|---|
| NOTE: Refer to Belt Dressing Notice in Cautions and Notices. DEFINITION: The following items are indications of drive belt vibration: The vibration is engine-speed related. The vibration may be sensitive to accessory load. | |||
| 1 | Did you review the Drive Belt Symptom operation and perform the necessary inspections? | Go to Step 2 | Go to Symptoms - Engine Mechanical |
| 2 | Verify that the vibration is engine related. Does the engine make the vibration? | Go to Step 3 | Go to Diagnostic Aids |
| 3 | Remove the drive belt. Refer to Drive Belt Replacement Operate the engine for no longer than 30 to 40 seconds. Does the engine still make the vibration? | Go to Diagnostic Starting Point - Vibration Diagnosis and Correction in Vibration Diagnosis and Correction | Go to Step 4 |
| 4 | Inspect the drive belt for wear, damage, debris build-up and missing drive belt ribs. Did you find any of these conditions? | Go to Step 5 | Go to Step 6 |
| 5 | Install a new drive belt. Refer to Drive Belt Replacement Did you complete the replacement? | Go to Step 11 | Go to Step 6 |
| 6 | Inspect for improper, loose or missing fasteners. Did you find any of these conditions? | Go to Step 7 | Go to Step 8 |
| 7 | Tighten any loose fasteners. Replace improper or missing fasteners. Refer to Fastener Tightening Specifications . Did you complete the repair? | Go to Step 11 | Go to Step 8 |
| 8 | Inspect for damaged fan blades or bent fan clutch shaft, if the fan is belt driven. Refer to Cooling Fan and Shroud Replacement Did you find and correct the condition? | Go to Step 11 | Go to Step 9 |
| 9 | Inspect for a bent water pump shaft, if the water pump is belt driven. Refer to Water Pump Replacement (LL8) or Water Pump Replacement (LM4) . Did you find and correct the condition? | Go to Step 11 | Go to Step 10 |
| 10 | Inspect for bent or cracked brackets. Did you find and correct the condition? | Go to Step 11 | Go to Diagnostic Aids |
| 11 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | Go to Step 3 |
| NOTE |
|---|
| Refer to Belt Dressing Notice in Cautions and Notices. |
Drive Belt Vibration Diagnosis
The number(s) below refer to the step number(s) on the diagnostic table.
- 2: This inspection is to verify the condition of the drive belt. Damage may of occurred to the drive belt when the drive belt fell off. The drive belt may of been damaged, which caused the drive belt to fall off. Inspect the belt for cuts, tears, sections of ribs missing, or damaged belt plys.
- 4: Misalignment of the pulleys may be caused from improper mounting of the accessory drive component, incorrect installation of the accessory drive component pulley, or the pulley bent inward or outward from a previous repair. Test for a misaligned pulley using a straight edge in the pulley grooves across two or three pulleys. If a misaligned pulley is found refer to that accessory drive component for the proper installation procedure of that pulley.
- 5: Inspecting the pulleys for being bent should include inspecting for a dent or other damage to the pulleys that would prevent the drive belt from not seating properly in all of the pulley grooves or on the smooth surface of a pulley when the back side of the belt is used to drive the pulley.
- 6: Accessory drive component brackets that are bent or cracked will let the drive belt fall off.
- 7: Inspecting of the fasteners can eliminate the possibility that a wrong bolt, nut, spacer, or washer was installed. Missing. loose, or the wrong fasteners may cause pulley misalignment from the bracket moving under load. Over tightening of the fasteners may cause misalignment of the accessory component bracket.
| Step | Action | Yes | No |
|---|---|---|---|
| NOTE: Refer to Belt Dressing Notice in Cautions and Notices. DEFINITION: The drive belt falls off the pulleys or may not ride correctly on the pulleys. | |||
| 1 | Did you review the Drive Belt Symptom operation and perform the necessary inspections? | Go to Step 2 | Go to Symptoms - Engine Mechanical |
| 2 | Inspect for a damaged drive belt. Did you find the condition? | Go to Step 3 | Go to Step 4 |
| 3 | Install a new drive belt. Refer to Drive Belt Replacement . Does the drive belt continue to fall off? | Go to Step 4 | System OK |
| 4 | Inspect for misalignment of the pulleys. Did you find and repair the condition? | Go to Step 12 | Go to Step 5 |
| 5 | Inspect for a bent or dented pulley. Did you find and repair the condition? | Go to Step 12 | Go to Step 6 |
| 6 | Inspect for a bent or a cracked bracket. Did you find and repair the condition? | Go to Step 12 | Go to Step 7 |
| 7 | Inspect for improper, loose or missing fasteners. Did you find loose or missing fasteners? | Go to Step 8 | Go to Step 9 |
| 8 | Tighten any loose fasteners. Replace improper or missing fasteners. Refer to Fastener Tightening Specifications . Does the drive belt continue to fall off? | Go to Step 9 | System OK |
| 9 | Test the drive belt tensioner for operating correctly. Refer to Drive Belt Tensioner Diagnosis . Does the drive belt tensioner operate correctly? | Go to Step 11 | Go to Step 10 |
| 10 | Replace the drive belt tensioner. Refer to Drive Belt Tensioner Replacement . Does the drive belt continue to fall off? | Go to Step 11 | System OK |
| 11 | Inspect for failed drive belt idler and drive belt tensioner pulley bearings. Did you find and repair the condition? | Go to Step 12 | Go to Diagnostic Aids |
| 12 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | Go to Step 2 |
| NOTE |
|---|
| Refer to Belt Dressing Notice in Cautions and Notices. |
Drive Belt Falls Off Diagnosis
The number(s) below refer to the step number(s) on the diagnostic table.
- 2: The inspection is to verify the drive belt(s) is correctly installed on all of the drive belt pulleys. Wear on the drive belt(s) may be caused by mis-positioning the drive belt(s) by one groove on a pulley.
- 3: The installation of a drive belt that is two wide or two narrow will cause wear on the drive belt. The drive belt ribs should match all of the grooves on all of the pulleys.
- 4: This inspection is to verify the drive belt(s) is not contacting any parts of the engine or body while the engine is operating. There should be sufficient clearance when the drive belt accessory drive components load varies. The drive belt(s) should not come in contact with an engine or a body component when snapping the throttle.
| Step | Action | Yes | No |
|---|---|---|---|
| NOTE: Refer to Belt Dressing Notice in Cautions and Notices. DEFINITION: Wear at the outside ribs of the drive belt due to an incorrectly installed drive belt. | |||
| 1 | Did you review the Drive Belt Symptom operation and perform the necessary inspections? | Go to Step 2 | Go to Symptoms - Engine Mechanical |
| 2 | Inspect the drive belt(s) for the proper installation. Refer to Drive Belt Replacement . Did you find this condition? | Go to Step 5 | Go to Step 3 |
| 3 | Inspect for the proper drive belt. Did you find this condition? | Go to Step 5 | Go to Step 4 |
| 4 | Inspect for the drive belt rubbing against a bracket, hose, or wiring harness. Did you find and repair the condition? | Go to Step 6 | Go to Diagnostic Aids |
| 5 | Replace the drive belt. Refer to Drive Belt Replacement . Did you complete the replacement? | Go to Step 6 | |
| 6 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | |
| NOTE |
|---|
| Refer to Belt Dressing Notice in Cautions and Notices. |
Drive Belt Excessive Wear Diagnosis
Crankcase Ventilation System Description
A closed crankcase ventilation system is used in order to provide a more complete scavenging of crankcase vapors. Fresh air from the throttle body is supplied to the crankcase, mixed with blow-by gases, and then passed through a crankcase ventilation pipe/passage into the intake manifold.
Results of Incorrect Operation
A plugged PCV Pipe/passage way may cause
- Rough idle
- Stalling or slow idle speed
- Oil leaks
- Sludge in engine
Drive Belt System Description
The drive belt system consists of the following components
- The drive belt
- The drive belt tensioner
- The drive belt idler pulley
- The crankshaft balancer pulley
- The accessory drive component mounting brackets
- The accessory drive components The power steering pump, if belt driven The generator The A/C compressor, if equipped The engine cooling fan, if belt driven The water pump, if belt driven The vacuum pump, if equipped The air compressor, if equipped
The drive belt system may use one belt or two belts. The drive belt is thin so that it can bend backwards and has several ribs to match the grooves in the pulleys. There also may be a V-belt style belt used to drive certain accessory drive components. The drive belts are made of different types of rubbers (chloroprene or EPDM) and have different layers or plys containing either fiber cloth or cords for reinforcement.
Both sides of the drive belt may be used to drive the different accessory drive components. When the back side of the drive belt is used to drive a pulley, the pulley is smooth.
The drive belt is pulled by the crankshaft balancer pulley across the accessory drive component pulleys. The spring loaded drive belt tensioner keeps constant tension on the drive belt to prevent the drive belt from slipping. The drive belt tensioner arm will move when loads are applied to the drive belt by the accessory drive components and the crankshaft.
The drive belt system may have an idler pulley, which is used to add wrap to the adjacent pulleys. Some systems use an idler pulley in place of an accessory drive component when the vehicle is not equipped with the accessory.
Exhaust Camshaft Position Actuator Description
Camshaft phasing allows the further optimization of performance, fuel economy and emissions without compromising overall engine response and driveability. Variable valve timing also contributes to a reduction in exhaust emissions. It optimizes exhaust and inlet valve overlap and eliminates the need for an exhaust gas recirculation (EGR) system.
The camshaft position actuator is a hydraulic vane-type actuator that changes the camshaft lobe timing relative to the camshaft drive sprocket. Engine oil is directed by a camshaft position actuator oil control valve to the appropriate passages in the camshaft position actuator. Oil acting on the vane in the camshaft position actuator, rotates the camshaft relative to the sprocket. At idle, the camshaft is at the default or "home" position. At this position, the exhaust camshaft is fully advanced to minimize valve overlap for smooth idle. The camshaft position actuator incorporates an integral trigger wheel, which is sensed by the camshaft position sensor to accurately determine the position of the camshaft.
The camshaft position actuator control valve directs oil from the oil feed in the head to the camshaft position actuator. A filter screen protects each oil port from any contamination in the oil supply. During start-up, when little oil pressure is available, an internal spring loaded locking pin keeps the rotor and stator locked together in the home position. When phasing is desired oil pressure is applied to the phaser unlocking the pin.
The camshaft front journal has a drilled oil hole to allow camshaft position actuator control oil to transfer from the cylinder head to the camshaft position actuator. Oil in this oil passage is used to move the camshaft position actuator to the default or home position. The camshaft position actuator is mounted to the front end of the camshaft and the timing notch in the nose of the camshaft aligns with the dowel pin in the camshaft position actuator to ensure proper cam timing and camshaft position actuator oil hole alignment.