Engine System-General Information: Diagnosis Ford Focus I рестайлинг

Inspection And Verification

1. Verify the customer concern by operating the engine to duplicate the condition.
2. Visually inspect for obvious signs of mechanical damage. Refer to the following chart. VISUAL INSPECTION Mechanical Engine coolant leaks Engine oil leaks Fuel leaks Damaged or severely worn parts Loose mounting bolts, studs and nuts
3. If the inspection reveals obvious concerns that can be readily identified, repair as necessary.
4. If the concerns remain after the inspection, determine the symptoms and go to the «SYMPTOM CHART»(ref-207747-S06443244882005120100000) .

Symptom Chart

SYMPTOM CHART

Compression Test-Compression Gauge Check

1. Make sure the oil in the crankcase is of the correct viscosity and at the correct level and that the battery is correctly charged. Operate the vehicle until the engine is at normal operating temperature. Turn the ignition switch to the OFF position, then remove all the spark plugs.
2. Set the throttle plates in the wide-open position.
3. Install a compression gauge in the No. 1 cylinder.
4. Install an auxiliary starter switch in the starting circuit. With the ignition switch in the OFF position, and using the auxiliary starter switch, crank the engine a minimum of five compression strokes and record the highest reading. Note the approximate number of compression strokes required to obtain the highest reading.
5. Repeat the test on each cylinder, cranking the engine approximately the same number of compression strokes.

Compression Test-Test Results

The indicated compression pressures are considered within specification if the lowest reading cylinder is at least 75 percent of the highest reading. Refer to the COMPRESSION PRESSURE LIMIT CHART .

Compression Test-Interpreting Compression Readings

1. If compression improves considerably, piston rings are faulty.
2. If compression does not improve, valves are sticking or seating incorrectly.
3. If two adjacent cylinders indicate low compression pressures and squirting oil on each piston does not increase compression, the head gasket may be leaking between cylinders. Engine oil or coolant in cylinders could result from this condition. Use the compression pressure limit chart when checking cylinder compression so that the lowest reading is within 75 percent of the highest reading.

Oil Consumption Test

The following diagnostic procedure is used to determine the source of excessive oil consumption.

1. Define excessive oil consumption, such as the number of miles driven per liter (quart) of oil used. Also determine the customer's driving habits, such as sustained high speed operation, towing, extended idle and other considerations.
2. Verify that the engine has no external oil leaks as described under «ENGINE OIL LEAKS»(ref-207747-S15483688012005120100000) in Diagnosis and Testing.
3. Verify that the engine has the correct oil level.
4. Verify that the engine is not being run in an overfilled condition. Check the oil level at least five minutes after a hot shutdown with the vehicle parked on a level surface. In no case should the level be above the top of the cross-hatched area and the letter "F" in FULL. If significantly overfilled, carry out the following step, substep 1 to 4.
5. Carry out an oil consumption test: Drain engine oil, remove oil bypass filter and fill with one liter less than the recommended amount. Run the engine for three minutes (10 minutes if cold), and allow oil to drain back for at least five minutes with vehicle parked on level surface. Remove the oil level indicator and wipe clean. (Do not wipe with anything contaminated with silicone compounds.) Install the oil level indicator, making sure to seat the oil level indicator firmly in the oil level indicator tube. Remove the oil level indicator and draw a mark on the back (unmarked) surface at the indicated oil level. (This level should be about the same as the ADD mark on the face of the oil level indicator.) Add one liter of oil. Start the engine and allow to idle for at least two minutes. Shut off the engine and allow the engine oil to drain back for at least five minutes. Mark the oil level dipstick, using the procedure above. (This level may range from slightly below the top of the cross-hatched area to slightly below the letter "F" in FULL.) Record the vehicle's mileage. Instruct the customer to drive the vehicle as usual and: check the oil level regularly at intervals of 160-240 km (100-150 miles). return to the service point when the oil level drops below the lower (ADD) mark on the oil level indicator. add only full liters of the same oil in an emergency. Note the mileage at which the oil is added.
6. Check the oil level under the same conditions and at the same location as in steps above. Measure the distance from the oil level to the upper mark on the oil level indicator and record. Measure the distance between the two scribe marks and record. Divide the first measurement by the second. Divide the distance driven during the oil test by the result. This quantity is the approximate oil consumption rate in kilometers per liter or in miles per quart. If the oil consumption rate is unacceptable, go to the next step.
7. Check the positive crankcase ventilation (PCV) system. Make sure the system is not plugged.
8. Check for plugged oil drain-back holes in the cylinder head and cylinder block.
9. If the condition still exists after carrying out the above tests, go to the next step.
10. Carry out a cylinder compression test. Refer to «COMPRESSION TEST»(ref-207747-S23198178182005120100000) . This can help determine the source of oil consumption such as valves, piston rings or other areas.
11. Check valve guides for excessive guide clearance. Install all valve stem oil seals new after verifying valve guide clearance.
12. Worn or damaged internal engine components can cause excessive oil consumption. Small deposits of oil on the tips of the spark plugs can be a clue to internal oil consumption. If internal oil consumption still persists, proceed as follows. Remove the engine from the vehicle and place it on an engine work stand. Remove the cylinder head and oil pan. Refer to «ENGINE -- 2.0L ZETEC»(ref-234423) , «ENGINE -- 2.0L SPI»(ref-234425) , «ENGINE -- SVT»(ref-234426) , or «ENGINE-- 2.3L»(ref-234427) for the procedure. Check the piston ring clearance, ring gap and ring orientation. Repair as necessary. Check the for excessive bearing clearance, ring gap and ring orientation. Repair as necessary.
13. Carry out oil consumption test as described to confirm oil consumption concern has been resolved.

Oil Pressure Test

1. Disconnect and remove the oil pressure sensor from the engine.
2. Connect the Engine Oil Pressure Gauge to the oil pressure sender oil galley port.
3. Run the engine until normal operating temperature is reached.
4. Run the engine at the specified RPM and record the gauge reading.
5. The oil pressure should be within specification; refer to the specification chart in «ENGINE -- 2.0L ZETEC»(ref-234423) , «ENGINE -- 2.0L SPI»(ref-234425) , «ENGINE -- SVT»(ref-234426) , or «ENGINE-- 2.3L»(ref-234427) .
6. If the pressure is not within specification, check the following possible sources: insufficient oil oil leakage worn or damaged oil pump oil pump screen cover and tube excessive main bearing clearance excessive connecting rod bearing clearance

Intake Manifold Vacuum Test

Run the engine until normal operating temperature is reached. Connect the Vacuum/Pressure Tester 164-R0253 or equivalent to the intake manifold. Run the engine at the specified idle speed.

The vacuum gauge should read between 51 - 74 kpa (15-22 in-Hg) depending upon the engine condition and the altitude at which the test is carried out. Subtract 4.0193 kPa (1 in-Hg) from the specified reading for every 304.8 m (1000 feet) of elevation above sea level.

The reading should be steady. As necessary, adjust the gauge damper control (where used) if the needle is fluttering rapidly. Adjust damper until needle moves easily without excessive flutter.

Piston Inspection

1. Carry out a visual inspection. Clean the piston skirt, pin bush, ring grooves and crown and check for wear or cracks. If there are signs of wear on the piston skirt, check whether the connecting rod is twisted or bent.

Exhaust Manifold Cleaning and Inspection

1. Inspect the cylinder head joining flanges of the exhaust manifold for evidence of exhaust gas leaks.
2. Inspect the exhaust manifold for cracks, damaged gasket surfaces, or other damage that would make it unfit for further use.

Scheme 1

1. Inspect bearings for the following defects. Cratering - fatigue failure Spot polishing - incorrect seating. Imbedded dirt engine oil. Scratching - dirty engine oil. Base exposed - poor lubrication. Both edges worn - journal damaged. One edge worn - journal tapered or bearing not seated.

Valve Seat Inspection

GENERAL EQUIPMENT

Scheme 2

1. Measure the width of the valve seat. Measure the valve seat width using the Valve seat width scale. If the value is not to specification rework the valve seat.

Scheme 3

1. Inspect the valve tappet for damage, especially in the indicated areas. If any damage is evident, inspect the camshaft lobes and valves for damage.
2. Replace components as necessary.