Compression Pressure Inspection
Note. If the there is lack of power, excessive oil consumption or poor fuel economy, measure the compression pressure.
Scheme 201
Scheme 202
Scheme 203
Scheme 204
Scheme 205
- Warm up and stop engine. Allow the engine to warm up to normal operating temperature.
- Disconnect the injector connectors (A).
- Disconnect the ignition coil connectors (A).
- Remove ignition coils (A).
- Remove spark plugs (A). Using a 16mm plug wrench, remove the 4 spark plugs.
- Check cylinder compression pressure. Insert a compression gauge into the spark plug hole. Fully open the throttle. While cranking the engine, measure the compression pressure. NOTE: Always use a fully charged battery to obtain engine speed of 200 rpm or more. Repeat steps ( 1 ) through ( 3 ) for each cylinder. NOTE: This measurement must be done in as short a time as possible. Compression pressure: 1, 275 kPa (13.0 kgf/cm 2 , 185 psi) Minimum pressure: 1, 128 kPa (11.5 kgf/cm 2 , 164 psi) Difference between each cylinder: 100 kPa (1.0 kgf/cm 2 , 15 psi) or less 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.
- Reinstall spark plugs. Tightening torque: 14.7 ~ 24.5 N.m (1.5 ~ 2.5 kgf.m, 10.8 ~ 18.1 lb-ft)
- Install ignition coils. Tightening torque: 9.8 ~ 11.8 N.m (1.0 ~ 1.2 kgf.m, 7.2 ~ 8.7 lb-ft)
- Connect the injector connectors and ignition coil connectors.
- Some DTCs may exist after the inspection test and may need to be manually cleared with GDS.
Troubleshooting
| Symption | Suspect area | Remedy |
|---|---|---|
| Engine misfire with abnormal internal lower engine noises | Worn crankshaft bearings Loose or out of specification engine flywheel | Replace the crankshaft and bearings as required. Repair or replace the flywheel as required. |
| Worn piston rings (Oil consumption may or may not cause the engine to misfire.) | Inspect the cylinder for a loss of compression. Repair or replace as required. | |
| Worn crankshaft thrust bearings | Replace the crankshaft and bearings as required | |
| Engine misfire with abnormal valve train noise | Stuck valves (Carbon buidup on the valve stem) | Repair or replace as required. |
| Excessive worn or mis-aligned timing chain | Replace the timing chain and sprocket as required. | |
| Worn camshaft lobes | Replace the camshaft. | |
| Engine misfire with coolant consumption | Faulty cylinder head gasket or other damage to the cylinder head and engine block cooling system Coolant consumption may or may not cause the engine to overheat | Inspect the cylinder head and engine block for damage to the coolant passages and/or a faulty head gasket. Repair or replace as required. |
| Engine misfire with excessive oil consumption | Worn valves, guides and/or valve stem oil seals | Repair or replace as required. |
| Worn piston rings (Oil consumption may or may not cause the engine to misfire) | Inspect the cylinder for a loss of compression. Repair or replace as required. | |
| Engine noise on start-up, but only lasting a few seconds (Check and compare with known good vehicle to determine normal condition.) | Incorrect oil viscosity | Drain the oil. Install the correct viscosity oil. |
| Worn crankshaft thrust bearing | Inspect the thrust bearing and crankshaft. Repair or replace as required. | |
| Upper engine noise, regardless of engine speed | Low oil pressure | Repair or replace as required. |
| Broken valve spring | Replace the valve spring. | |
| Worn or dirty valve lifters | Replace the valve lifters. | |
| Stretched or broken timing chain and/or damaged sprocket teeth | Replace the timing chain and sprockets. | |
| Worn timing chain tensioner, if applicable | Replace the timing chain tensioner as required. | |
| Worn camshaft lobes | Inspect the camshaft lobes. Replace the camshaft as required. | |
| Worn valve guides or valve stems | Inspect the valves and valve guides, then repair or replace as required. | |
| Stuck valves (Carbon on the valve stem or valve seat may cause the valve to stay open.) | Inspect the valves and valve guides, then repair or replace as required. | |
| Worn drive belt, idler, tensioner and bearing | Replace as required. | |
| Lower engine noise, regardless of engine speed | Low oil pressure | Repair or required. |
| Loose or damaged flywheel | Repair or replace the flywheel. | |
| Damaged oil pan, contacting the oil pump screen | Inspect the oil pan. Inspect the oil pump screen. Repair or replace as required. | |
| Oil pump screen loose, damaged or restricted | Inspect the oil pump screen. Repair or replace as required. | |
| Excessive piston-to-cylinder bore clearance | Inspect the piston, piston pin and cylinder bore. Repair or replace as required. | |
| Excessive piston pin-to-piston clearance | Inspect the piston, piston pin and the connecting rod. Repair or replace as required. | |
| Excessive connecting rod bearing clearance | Inspect the following components and repair or replace as required. The connecting rod bearings. The connecting rods. The crankshaft pin journals. | |
| Excessive crankshaft bearing clearance | Inspect the following components, and repair or replace as required. The crankshaft bearings. The crankshaft main journals. The cylinder block | |
| Incorrect piston, piston pin and connecting rod installation | Verify the piston pins and connecting rods are installed correctly. Repair as required. | |
| Engine noise under load | Low oil pressure | Repair or replace as required. |
| Excessive connecting rod bearing clearance | Inspect the following components and repair or replace as required: The connecting rod bearings The connecting rods The crankshaft | |
| Excessive crankshaft bearing clearance | Inspect the following components, and repair or replace as required: The crankshaft bearings The crankshaft main journals The cylinder block | |
| Engine is not cranked. Crankshaft does not rotate. | Hydraulically locked cylinder Coolant/antifreeze in cylinder Oil in cylinder Fuel in cylinder | Remove spark plugs and check for fluid. Inspect for broken head gasket. Inspect for cracked engine block or cylinder head. Inspect for a sticking fuel injector and/or leaking fuel regulator. |
| Broken timing chain and/or timing chain gears | Inspect timing chain and gears. Repair as required. | |
| Material in cylinder Broken valve Piston material Foreign material | Inspect cylinder for damaged components and/or foreign materials. Repair or replace as required. | |
| Seized crankshaft or connecting rod bearings | Inspect crankshaft and connecting rod bearing. Repair as required. | |
| Bent or broken connecting rod | Inspect connecting rods. Repair as required. | |
| Broken crankshaft | Inspect crankshaft. Repair as required. |