2.0L Engine - Service Information: Diagnosis Jeep Compass I

CYLINDER COMBUSTION PRESSURE LEAKAGE TEST

The combustion pressure leakage test provides an accurate means for determining engine condition.

Combustion pressure leakage testing will detect

1. Exhaust and intake valve leaks (improper seating).
2. Leaks between adjacent cylinders or into water jacket.
3. Any causes for combustion/compression pressure loss.

1. Check the coolant level and fill as required. DO NOT install the pressure cap.
2. Start and operate the engine until it attains normal operating temperature, then turn the engine OFF.
3. Clean spark plug recesses with compressed air.
4. Remove the spark plugs.
5. Remove the oil filler cap.
6. Remove the air cleaner.
7. Calibrate the tester according to the manufacturer's instructions. The shop air source for testing should maintain 483 kPa (70 psi) minimum, 1,379 kPa (200 psi) maximum, with 552 kPa (80 psi) recommended.
8. Perform the test procedures on each cylinder according to the tester manufacturer's instructions. While testing, listen for pressurized air escaping through the throttle body, tailpipe and oil filler cap opening. Check for bubbles in the coolant.
9. All gauge pressure indications should be equal, with no more than 25% leakage per cylinder.
10. FOR EXAMPLE: At 552 kPa (80 psi) input pressure, a minimum of 414 kPa (60 psi) should be maintained in the cylinder.

CYLINDER COMPRESSION PRESSURE TEST

The results of a cylinder compression pressure test can be utilized to diagnose several engine malfunctions.

Ensure the battery is completely charged and the engine starter motor is in good operating condition. Otherwise the indicated compression pressures may not be valid for diagnosis purposes.

1. Check engine oil level and add oil if necessary.
2. Drive the vehicle until engine reaches normal operating temperature. Select a route free from traffic and other forms of congestion, observe all traffic laws, and accelerate through the gears several times briskly.
3. Remove engine cover.
4. Disconnect coil electrical connectors and remove coils.
5. Remove all spark plugs from engine. As spark plugs are being removed, check electrodes for abnormal firing indicators fouled, hot, oily, etc. Record cylinder number of spark plug for future reference.
6. Disconnect injector electrical connectors.
7. Be sure throttle blade is fully open during the compression check.
8. Insert compression pressure adaptor 8116 or the equivalent, into the #1 spark plug hole in cylinder head. Connect the 0-500 psi (Blue) pressure transducer CH7059 with cable adaptors to the DRBIII®. For Special Tool identification, see «SPECIAL TOOLS»(ref-304329-S19569091372008110700000) .
9. Crank engine until maximum pressure is reached on gauge. Record this pressure as #1 cylinder pressure.
10. Repeat the previous step for all remaining cylinders.
11. Compression should not be less than 1034 kPa (150 psi) and not vary more than 25 percent from cylinder to cylinder.
12. If one or more cylinders have abnormally low compression pressures, repeat the compression test.
13. If the same cylinder or cylinders repeat an abnormally low reading on the second compression test, it could indicate the existence of a problem in the cylinder in question. The recommended compression pressures are to be used only as a guide to diagnosing engine problems. An engine should not be disassembled to determine the cause of low compression unless some malfunction is present.

ENGINE DIAGNOSIS - MECHANICAL

ENGINE DIAGNOSIS - PERFORMANCE

ENGINE OIL LEAK INSPECTION

Begin with a thorough visual inspection of the engine, particularly at the area of the suspected leak. If an oil leak source is not readily identifiable, the following steps should be followed

1. Do not clean or degrease the engine at this time because some solvents may cause rubber to swell, temporarily stopping the leak.
2. Add an oil soluble dye (use as recommended by manufacturer). Start the engine and let idle for approximately 15 minutes. Check the oil dipstick to make sure the dye is thoroughly mixed as indicated with a bright yellow color under a black light.
3. Using a black light, inspect the entire engine for fluorescent dye, particularly at the suspected area of oil leak. If the oil leak is found and identified, repair as necessary.
4. If dye is not observed, drive the vehicle at various speeds for approximately 24 km (15 miles), and repeat inspection.
5. If the oil leak source is not positively identified at this time , proceed with the AIR LEAK DETECTION TEST method as follows: Disconnect the fresh air hose (make-up air) at the cylinder head cover and plug or cap the nipple on the cover. Remove the PCV valve hose from the cylinder head cover. Cap or plug the PCV valve nipple on the cover. Attach an air hose with pressure gauge and regulator to the dipstick tube. CAUTION: Do not subject the engine assembly to more than 20.6 kPa (3 psi) of test pressure. Gradually apply air pressure from 1 psi to 2.5 psi maximum while applying soapy water at the suspected source. Adjust the regulator to the suitable test pressure that provides the best bubbles which will pinpoint the leak source. If the oil leak is detected and identified, repair per service information procedures. If the leakage occurs at the crankshaft rear oil seal area, refer to «INSPECTION FOR REAR SEAL AREA LEAKS»(ref-304329-S22395648522008110700000) .
6. If no leaks are detected, turn off the air supply. Remove the air hose, all plugs, and caps. Install the PCV valve and fresh air hose (make-up air). Proceed to next step.
7. Clean the oil off the suspect oil leak area using a suitable solvent. Drive the vehicle at various speeds approximately 24 km (15 miles). Inspect the engine for signs of an oil leak by using a black light.

Note. If oil leakage is observed at the dipstick tube to block location; remove the tube, clean and reseal using Mopar® Stud & Bearing Mount (press fit tube applications only), and for O-ring style tubes, remove tube and replace the O-ring seal.

INSPECTION FOR REAR SEAL AREA LEAKS

Since it is sometimes difficult to determine the source of an oil leak in the rear seal area of the engine, a more involved inspection is necessary. The following steps should be followed to help pinpoint the source of the leak.

If the leakage occurs at the crankshaft rear oil seal area

1. Disconnect the battery.
2. Raise the vehicle.
3. Remove torque converter or clutch housing cover and inspect rear of block for evidence of oil. Use a black light to check for the oil leak. If a leak is present in this area, remove transmission for further inspection. Circular spray pattern generally indicates seal leakage or crankshaft damage. Where leakage tends to run straight down, possible causes are a porous block, oil gallery cup plug, bedplate to cylinder block mating surfaces and seal bore. See proper repair procedures for these items.
4. If no leaks are detected, pressurize the crankcase as previously described in 5 under ENGINE OIL LEAK INSPECTION. CAUTION: Do not exceed 20.6 kPa (3 psi).
5. If the leak is not detected, very slowly turn the crankshaft and watch for leakage. If a leak is detected between the crankshaft and seal while slowly turning the crankshaft, it is possible the crankshaft seal surface is damaged. The seal area on the crankshaft could have minor nicks or scratches that can be polished out with emery cloth. CAUTION: Use extreme caution when crankshaft polishing is necessary to remove minor nicks and scratches. The crankshaft seal flange is especially machined to complement the function of the rear oil seal.
6. For bubbles that remain steady with shaft rotation, no further inspection can be done until disassembled.
7. After the oil leak root cause and appropriate corrective action have been identified, replace component(s) as necessary.

Scheme 25

Using a blunt tool (3) such as a drift and a hammer, strike the bottom edge of the cup plug (5). With the cup plug rotated, grasp firmly with pliers or other suitable tool (2) and remove plug (5).

Thoroughly clean inside of cup plug hole in cylinder head. Be sure to remove old sealer. Lightly coat inside of cup plug hole with Mopar® Stud and Bearing Mount (or equivalent). Make certain the new plug is cleaned of all oil or grease. Using proper drive plug, drive plug into hole so that the sharp edge of the plug is at least 0.5 mm (0.020 in.) inside the lead-in chamfer.

It is not necessary to wait for curing of the sealant. The cooling system can be refilled and the vehicle placed in service immediately.

Scheme 26

1. Use Mopar® Brake Parts Cleaner (or equivalent) sparingly to clean plug and block.
2. Coat plug threads with Mopar® Thread Sealant (or equivalent).
3. Install plug (2). The plug (2) is correctly installed when it is protruding 1 mm to flush with the block boss face (1).

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To ensure engine gasket sealing, proper surface preparation must be performed, especially with the use of aluminum engine components and multi-layer steel cylinder head gaskets.

Never use the following to clean gasket surfaces

1. Metal scraper (1).
2. Abrasive pad or paper (2) to clean cylinder block and head.
3. High speed power tool with an abrasive pad, a wire brush, or 3M Roloc™ Bristle Disc (white or yellow) (3).

Note. Multi-Layer Steel (MLS) head gaskets require a scratch free sealing surface.

Only use the following for cleaning gasket surfaces

1. Solvent or a commercially available gasket remover
2. Plastic or wood scraper (4).

Sealing surfaces must be free of grease or oil residue. Clean surfaces with Mopar® brake parts cleaner (or equivalent).

CYLINDER-TO-CYLINDER LEAKAGE TEST

To determine if an engine cylinder head gasket is leaking between adjacent cylinders, follow the procedures in CYLINDER COMPRESSION PRESSURE TEST . An engine cylinder head gasket leaking between adjacent cylinders will result in approximately a 50-70% reduction in compression pressure.

CYLINDER-TO-WATER JACKET LEAKAGE TEST

VISUAL TEST METHOD

With the engine cool, remove the coolant pressure cap. Start the engine and allow it to warm up until thermostat opens.

If a large combustion/compression pressure leak exists, bubbles will be visible in the coolant.

CHEMICAL TEST METHOD

Combustion leaks into the cooling system can also be checked by using combustion leak tester C-3685-A or equivalent. Perform test following the procedures supplied with the tool kit.

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1. Perform fuel system pressure release procedure before attempting any repairs . Refer to «STANDARD PROCEDURE»(ref-304342-S34730499872008110700000) .
2. Remove clean air hose and air cleaner housing (1). See «REMOVAL»(ref-304329-S37258294512008110700000) .
3. Disconnect negative cable from battery (3).
4. Drain cooling system. Refer to «STANDARD PROCEDURE»(ref-304343-S02124729692008110700000) .
5. Remove engine cover.
6. Remove coolant recovery bottle (3).
7. Remove and reposition power steering reservoir (2).
8. Remove power steering pump and reposition.
9. Remove windshield washer bottle (1).
10. Disconnect breather hose.
11. Disconnect PCV hose (4).
12. Disconnect ignition coil electrical connectors (1).
13. Remove cylinder head cover.
14. Raise vehicle.
15. Remove right splash shield.
16. Set engine to TDC (1).
17. Remove accessory drive belts. Refer to «REMOVAL»(ref-304343-S05780822912008110700000) .
18. Remove lower A/C compressor bolts if equipped.
19. Remove lower A/C compressor mount (2) if equipped.
20. Remove accessory drive belt lower idler pulley.
21. Remove crankshaft damper (2).
22. Remove water pump pulley (4).
23. Remove right side engine mount bracket (1) lower bolt.
24. Remove timing chain cover lower bolts (1).
25. Disconnect oxygen sensor electrical connector (3).
26. Remove exhaust pipe at manifold nuts (1) and remove pipe.
27. Lower vehicle.
28. Support engine with suitable jack.
29. Remove right engine mount through bolt (4).
30. Remove right engine mount to mount bracket bolts (3).
31. Remove right engine mount adapter (2).
32. Remove accessory drive upper idler pulley.
33. Remove right upper engine mount bracket (1).
34. Remove accessory drive belt tensioner.
35. Remove upper timing chain cover retaining bolts.
36. Remove timing chain cover. NOTE: If the timing chain plated links can no longer be seen, the timing chain links corresponding to the timing marks must be marked prior to removal if the chain is to be reused.
37. Mark chain link (1) corresponding to camshaft timing mark.
38. Mark chain link (3) corresponding to crankshaft timing mark (2).
39. Remove timing chain tensioner (5).
40. Remove timing chain (2).
41. Remove timing chain guides (4,6).
42. Disconnect fuel line at the fuel rail (2).
43. Disconnect fuel injector electrical connectors (3).
44. Disconnect top engine electrical connectors and reposition harness.
45. Remove fuel rail.
46. Remove throttle body support bracket retaining bolt (2).
47. Disconnect electronic throttle control electrical connector.
48. Disconnect map sensor electrical connector.
49. Disconnect vacuum lines at intake.
50. Remove intake manifold retaining bolts.
51. Remove upper radiator hose retaining bolt (1).
52. Remove intake manifold.
53. Remove coolant outlet manifold and set aside.
54. Remove ground strap (1) at right rear of cylinder head.
55. Remove exhaust manifold. See «REMOVAL»(ref-304329-S19547876932008110700000) .
56. Remove camshafts. See «REMOVAL»(ref-304329-S15893420982008110700000) NOTE: All of the cylinder head bolts have captured washers EXCEPT the front two (1).
57. Remove cylinder head bolts.
58. Remove cylinder head from engine block.
59. Remove front cylinder head bolt washers (1).
60. Inspect and clean cylinder head and block sealing surfaces. Refer to «CLEANING»(ref-304329-S27114866232008110700000) and «INSPECTION»(ref-304329-S09174496122008110700000) .

Note. Ensure cylinder head bolt holes in the block are clean, dry (free of residual oil or coolant), and threads are not damaged.

HYDRAULIC LASH ADJUSTER NOISE DIAGNOSIS

A tappet-like noise may be produced from incorrect valve lash. See STANDARD PROCEDURE .

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1. Remove engine cover.
2. Remove cylinder head cover. See «REMOVAL»(ref-304329-S10843827882008110700000) .
3. Rotate camshaft so lobes are vertical (1).
4. Check clearance using feeler gauges.
5. Repeat for all tappets and record readings.
6. If clearance was too small, refer to «CLEARANCE TOO SMALL»(ref-304329-S32151511692008110700000) .
7. If clearance was too large, refer to «CLEARANCE TOO LARGE»(ref-304329-S25152327662008110700000) .

Scheme 46

1. Remove camshafts. See «REMOVAL»(ref-304329-S15893420982008110700000) .
2. Specification - clearance = change.
3. Decrease tappet thickness by change figure.
4. Install camshafts. See «INSTALLATION»(ref-304329-S11114030262008110700000) .
5. Verify that valve lash is correct.

DIAGNOSIS AND TESTING-VVT OIL PRESSURE

This test can be used to help diagnose VVT faults.

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1. Disconnect and remove oil pressure sensor (1). CAUTION: Threads in block are 1/8"-28 British Standard Pipe (BSP). Do not install a National Pipe Thread (NPT) threaded adapter, this could crack the cylinder block.
2. Install an 1/8-28 BSP male to 1/8-27 female threaded adapter (2).
3. Install oil pressure gauge (1).
4. Start engine and record oil pressure. CAUTION: If oil pressure is 0 at idle, do not perform the 3000 RPM test
5. If oil pressure is 0 at idle, shut off engine. check for pressure relief valve stuck open, a clogged oil pick-up screen.
6. Remove oil pan and inspect for debris. See «REMOVAL»(ref-304329-S23187716552008110700000) .
7. Remove oil pressure relief valve, and inspect. If damaged replace pressure relief valve. See «REMOVAL»(ref-304329-S13142227132008110700000)
8. If pressure relief valve is okay, replace balance shaft module assembly. See «REMOVAL»(ref-304329-S24666377072008110700000) .
9. After test is complete, remove test gauge (1) and fitting (2).
10. Install oil pressure sensor and electrical connector.