This professional tool (model KT6147) is engineered to measure the cylinder pressure of automotive engines, functioning as a specialized device for detecting engine cylinder pressure. It helps assess key engine components (e.g., piston rings, valves, cylinder seals) by providing accurate pressure readings, supporting efficient engine performance diagnostics.

How to use

1. Start the engine until it reaches normal operating temperature.

2. Loosen all spark plugs by one to two turns, then crank the engine with the starter motor (do not start the engine) for 5-10 seconds. This will blow away dirt around the spark plug seats to prevent it from falling into the cylinders.

3. Carefully remove all spark plugs; visual inspection of the spark plugs can reveal many issues:  If the spark plug is fouled with oil, it indicates a damaged piston ring or worn valve guide; a burnt spark plug means ignition timing is off.

4. Fully open the carburetor throttle to check if the result matches expectations.

5. When cranking the engine with the starter motor, tightly press the pressure gauge's rubber fire extinguisher against the spark plug hole.

6. Crank the engine with the starter motor until 4 compression strokes are completed; record the readings for each stroke, noting the values of the first and fourth strokes. Ensure the battery is fully charged, and the starter motor is in good condition to crank the engine at normal speed—slow cranking will lead to inaccurate test results.

7. After reading the gauge, pull the pressure relief valve on the gauge to release pressure.

Results:

In the following situations, the engine is in good condition.

1. The pressure in the first stroke is 50-70 PSI.

2. The final pressure falls within the specified technical range.

3. The difference between the highest and lowest pressures is minimal.

Note: The cylinder-to-cylinder pressure difference should not exceed 10-15 PSI (for Ford vehicles, the minimum value should be no less than 70% of the maximum value).

In the following situations, it indicates that there is a problem with the engine:

1. The low pressure in the first stroke and the cumulative pressure per stroke is only 10-20 PSL. This indicates that the valve is stuck or the valve seat is burned.

2. The pressure in one cylinder or all cylinders is low. Inject a small amount of engine oil into the cylinder and check if the piston ring or the cylinder wall is damaged, or if the engine oil has blocked the tiny leaks around the piston ring. If the result is still very low, then the problem lies in the valve or the cylinder head gasket. If there is only a slight increase, then the piston ring, the valve, or the cylinder head gasket is damaged, or all three may be damaged.

3. The higher pressure than normal is caused by excessive carbon deposits in the cylinder.

4. If the reading is low, it may be due to a problem with the installation of the piston ring.