| Compession Pressure Inspection |
| •
| If the there is lack of power, excessive oil consumption or poor fuel economy, measure the compression pressure. |
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| 1. | Start the engine and turn the coolant temperature to 80 - 95 °C and stop. |
| 2. | Remove the engine cover (A). 
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| 3. | Disconnect the injector connector (A). 
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| 4. | Remove the ignition coils. (Refer to Engine Electical System - "Ignition Coil") |
| 5. | Remove spark plugs. (Refer to Engine Electrical System - "Spark Plug") |
| 6. | Check the cylinder compression pressure. | (1) | Insert a compression gauge into the spark plug hole. 
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| (2) | Fully open the throttle valve. |
| (3) | While cranking the engine, measure the compression pressure. | •
| Always use a fully charged battery to obtain engine speed of 200 rpm or more. |
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| (4) | Repeat steps (1) through (3) for each cylinder. | •
| If you need to check the compression pressure for more than three times, restart the engine to restore the lubrication condition to be normal and then check the compression pressure again. |
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Compression pressure Standard : 1,127.76 kPa (11.5 kgf/cm², 164 psi) (200-250 rpm) Minimum : 980.66 kPa (10.0 kgf/cm², 142 psi) Difference between each cylinder : 98 kPa (1.0 kgf/cm², 14 psi) or less |
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| (5) | If the cylinder compression in 1 or more cylinders is low, pour a small amount of engine oil into the cylinder through the spark plug hole and repeat steps (1) through (3) for cylinders with low compression. | •
| If adding oil helps the compression, it is likely that the piston rings and/or cylinder bore are worn or damaged. |
| •
| If pressure stays low, a valve may be sticking or seating is improper, or there may be leakage past the gasket. |
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| 7. | Install the spark plugs. (Refer to Engine Electrical System - "Spark Plug") |
| 8. | Install the ignition coil. (Refer to Engine Electical System - "Ignition Coil") |
| 9. | Connect the injector connector (A).
|
| 10. | Some DTCs may exist after the inspection test and may need to be manually cleared with diagnostic tool. |
| 11. | Install the engine cover. (Refer to Engine and Transaxle Assembly - "Engine Cover") |
Specifications
Description
Specifications
Limit
General
TypeIn-line, DOHC Number of c ...
Troubleshooting
Symptom
Suspect area
Remedy
Engine misfire with abnormal internal lower engine noises.Loose or improperl ...
Hyundai Elantra CN7: Repair procedures
