Contents: Compression tester for gasoline…⤓ Checking the compression in the…⤓ Compression tester for diesel engines ⤓ Measuring compression on diesel…⤓
Compression tester for gasoline engines
Checking the compression in the cylinders of gasoline engines
1. Warm up the engine to normal operating temperature.
2. Remove the spark plugs.
3. Disconnect the high-voltage wire from the ignition coil.
4. Open the throttle valve fully.
5. Screw the compression gauge into the spark plug hole of the 1st cylinder.
6. Ask an assistant to press the throttle pedal and turn on the starter (on carburetor and injection engines). The starter should engage two or three times for a short time.
7. Determine the pressure gauge reading at the end of each starter cycle and record the maximum reading. Repeat the procedure for each cylinder. The compression values in the cylinders should be 10.3–11.7 atm (maximum 7.2 atm). Compression values in individual cylinders should not differ by more than 10%.
8. If the compression is below normal, pour about 1 tablespoon of engine oil into the cylinder and repeat the measurements. If the compression has increased, this indicates wear or breakage of the piston rings, or increased wear of the cylinder walls. If the pressure has not changed, then the reason is that the valves do not fit tightly to the seats (valve mechanism repair required), or damage to the cylinder head gasket near the cylinder. If there is a low compression value in two adjacent cylinders, which does not change when adding oil, then the cylinder head gasket is damaged.
Compression tester for diesel engines
The verification procedure is no different from that described above, but has its own characteristics.
(The material is based on data from the website mitsubishiman.ru)
Measuring compression on diesel engines
1. For diesel engines, a special compression tester designed for much higher pressures should be used.
2. The tubes and injectors with ring gaskets should be removed from all cylinders.
3. Make sure the air bleed valve on the compression gauge is closed.
4. When installing the injectors, replace the O-rings.