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Engine Compression Test and Cylinder Leakage Test




Engine Compression Test and Cylinder Leakage Test

1. Engine Compression Test:

Engine Compression Test
NOTE: After this test, you must reset the engine control module (ECM)/powertrain control module (PCM). Otherwise, the ECM/PCM will continue to stop the fuel injectors from operating.

-1. Warm up the engine to normal operating temperature (cooling fan comes on twice).

-2. Turn the ignition switch to LOCK (0).

-3. Connect the Honda Diagnostic System (HDS) to the data link connector (DLC).

-4. Turn the ignition switch to ON (II).

-5. Make sure the HDS communicates with the vehicle and the ECM/PCM. If it does not communicate, troubleshoot the DLC circuit.

-6. Select ALL INJECTORS STOP in the PGM-FI, INSPECTION menu with the HDS.

-7. Turn the ignition switch to LOCK (0).

-8. Remove all ignition coils.

-9. Remove all spark plugs.

-10. Attach a compression gauge to the spark plug hole of the No. 1 cylinder.










-11. Hold the throttle fully open, then crank the engine with the starter motor and count the compression strokes required to reach maximum compression (normally between 6-10).
NOTE: If the compression gauge does not hold pressure, check for a missing or damaged Schrader valve in the cylinder side of the compression gauge adaptor hose, or in the gauge pressure bleed off port.

-12. Record the compression value below, and then measure the compression on the remaining cylinders using the same number of compression strokes. Record their values below.




















Is the compression and their variation are OK?
-YES- The engine compression and all cylinder compression value's variation are OK. Go to step 2 (Cylinder Leakage Test).
-NO- Record the compression test result, then go to step 2 (Cylinder Leakage Test).

2. Cylinder leakage test (No. 1 cylinder):

Cylinder leakage test (No. 1 cylinder)
CAUTION:
If the piston is not exactly at top dead center, applying air pressure to the cylinder will rotate the crankshaft. Be certain to remove your tools from the crankshaft, and stay clear of any potential rotating parts when applying the test pressure to the cylinder. Make certain that the vehicle is in P or N (or neutral) with the parking brake set.

NOTE:
* Ensure that the Schrader valve is removed from the cylinder side of the adaptor hose. All of your readings will show 0 % leakage if the valve is left in place during testing.
* Disconnect any shop exhaust hoses from the vehicle. The vacuum from these hoses may cause an incorrect diagnosis.

-1. Remove the cylinder head cover.

-2. For R18Z1 engine: Set the No. 1 piston at top dead center (TDC). The "UP" mark (A) on the camshaft sprocket should be at the top, and the TDC grooves (B) on the camshaft sprocket should line up with the top edge of the head.





-3. For K24Z7 engine: Set the No. 1 piston at top dead center (TDC). The punch mark (A) on the variable valve timing control (VTC) actuator and the punch mark (B) on the exhaust camshaft sprocket should be at the top. Align the TDC marks (C) on the VTC actuator and the exhaust camshaft sprocket.





-4. Insert the adaptor hose into the No. 1 spark plug hole, and connect the hose to the cylinder leakage tester. Record the cylinder leakage for the No. 1 cylinder. (The cylinder leakage tester must also be connected to shop air with a minimum of 100 psi.)

Is the leakage greater than 10 %?
-YES- The cylinder leakage is too high. Listen for escaping air in each of these areas: throttle body (fully open), exhaust pipe, radiator (cap removed), and rocker area. Record the area where the majority of the air is escaping. Go to step 3.
-NO- The cylinder leakage is acceptable, Go to step 3.

3. Cylinder leakage test (No. 3 cylinder):

Cylinder leakage test (No. 3 cylinder)
CAUTION:
If the piston is not exactly at top dead center, applying air pressure to the cylinder will rotate the crankshaft. Be certain to remove your tools from the crankshaft, and stay clear of any potential rotating parts when applying the test pressure to the cylinder. Make certain that the vehicle is in P or N (or neutral) with the parking brake set.

NOTE:
* Ensure that the Schrader valve is removed from the cylinder side of the adaptor hose. All of your readings will show 0 % leakage if the valve is left in place during testing.
* Disconnect any shop exhaust hoses from the vehicle. The vacuum from these hoses may cause an incorrect diagnosis.

-1. Rotate the crankshaft 180° clockwise (camshaft pulley turns 90°). For R18Z1 engine, align the No. 3 piston TDC groove (A) on the camshaft sprocket with the top edge of the head.










-2. Insert the adaptor hose into the No. 3 spark plug hole, and connect the hose to the cylinder leakage tester. Record the cylinder leakage for the No. 3 cylinder.

Is the leakage greater than 10 %?
-YES- The cylinder leakage is too high. Listen for escaping air in each of these areas: throttle body (fully open), exhaust pipe, radiator (cap removed), and rocker area. Record the area where the majority of the air is escaping. Go to step 4.
-NO- The cylinder leakage is acceptable. Go to step 4.

4. Cylinder leakage test (No. 4 cylinder):

Cylinder leakage test (No. 4 cylinder)
CAUTION:
If the piston is not exactly at top dead center, applying air pressure to the cylinder will rotate the crankshaft. Be certain to remove your tools from the crankshaft, and stay clear of any potential rotating parts when applying the test pressure to the cylinder. Make certain that the vehicle is in P or N (or neutral) with the parking brake set.

NOTE:
* Ensure that the Schrader valve is removed from the cylinder side of the adaptor hose. All of your readings will show 0 % leakage if the valve is left in place during testing.
* Disconnect any shop exhaust hoses from the vehicle. The vacuum from these hoses may cause an incorrect diagnosis.

-1. Rotate the crankshaft 180° clockwise (camshaft pulley turns 90°). For R18Z1 engine, align the No. 4 piston TDC groove (A) on the camshaft sprocket with the top edge of the head.










-2. Insert the adaptor hose into the No. 4 spark plug hole, and connect the hose to the cylinder leakage tester. Record the cylinder leakage for the No. 4 cylinder.

Is the leakage greater than 10 %?
-YES- The cylinder leakage is too high. Listen for escaping air in each of these areas: throttle body (fully open), exhaust pipe, radiator (cap removed), and rocker area. Record the area where the majority of the air is escaping. Go to step 5.
-NO- The cylinder leakage is acceptable, Go to step 5.

5. Cylinder leakage test (No. 2 cylinder):

Cylinder leakage test (No. 2 cylinder)
CAUTION:
If the piston is not exactly at top dead center, applying air pressure to the cylinder will rotate the crankshaft. Be certain to remove your tools from the crankshaft, and stay clear of any potential rotating parts when applying the test pressure to the cylinder. Make certain that the vehicle is in P or N (or neutral) with the parking brake set.

NOTE:
* Ensure that the Schrader valve is removed from the cylinder side of the adaptor hose. All of your readings will show 0 % leakage if the valve is left in place during testing.
* Disconnect any shop exhaust hoses from the vehicle. The vacuum from these hoses may cause an incorrect diagnosis.

-1. Rotate the crankshaft 180° clockwise (camshaft pulley turns 90°). For R18Z1 engine, align the No. 2 piston TDC groove (A) on the camshaft sprocket with the top edge of the head.










-2. Insert the adaptor hose into the No. 2 spark plug hole, and connect the hose to the cylinder leakage tester. Record the cylinder leakage for the No. 2 cylinder.

Is the leakage greater than 10 %?
-YES- The cylinder leakage is too high. Listen for escaping air in each of these areas: throttle body (fully open), exhaust pipe, radiator (cap removed), and rocker area. Record the area where the majority of the air is escaping. Go to step 6.
-NO- The cylinder leakage is acceptable, Go to step 6.

6. Cylinder leakage result check:

Cylinder leakage result check
-1. Record your test results in a chart similar to the one below.









Does any cylinder have leakage greater than 10 %?
-YES- Go to step 8.
-NO- Go to step 7.

7. Cylinder compression result check

-1. Check your cylinder compression results.

Does the compression vary more than 29 psi between cylinders, or does any cylinder read below 135 psi?
-YES- The engine compression is low and cylinder leakage is normal. Check for each of these conditions:





-NO- The engine compression and cylinder leakage is normal. Remove the cylinder leak-down gauge from the spark plug hole. Reinstall the cylinder head cover, the spark plugs and the ignition coils.

8. Leakage area check:

Leakage area check
-1. Check your cylinder leakage results.

Is the majority of the air escaping from the exhaust pipe or throttle body?
-YES- Go to step 9.
-NO- Compare your test results (leakage area) to the chart below, and inspect/repair the associated components as needed.





9. Valve clearance check:

Valve clearance check
-1. Check the valve clearances on the problem cylinder(s).

Are the valve clearances OK?
-YES- Compare your test results to the chart below, and inspect/repair the associated components as needed.





-NO- Adjust the valve clearance, then go to step 10.

10. Cylinder leakage check:

Cylinder leakage check
-1. Recheck the leakage on the cylinders with high leakage.

Is the cylinder leakage within 10 %?
-YES- The cylinder leakage is normal. Remove the cylinder leak-down gauge from the spark plug hole. Reinstall the cylinder head cover, the spark plugs and the ignition coils.
-NO- Compare your test results (leakage area) to the chart below, and inspect/repair the associated components as needed.





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