Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
2011 Mazda RX8 2RTR-1.3LFACTORY OEM SERVICE PROCEDURE
Compression Check: Testing and Inspection
COMPRESSION INSPECTION [13B-MSP]
WARNING:
- Hot engines can cause severe burns. Be careful not to burn yourself during removal/installation of each component.
- Fuel vapor is hazardous. It can very easily ignite, causing serious injury and damage. Always keep sparks and flames away from fuel.
1. Remove the engine cover. Service and Repair
2. Verify that the battery is fully charged. Testing and Inspection
3. Warm up the engine.
4. Remove the trailing or leading side spark plug of the front and rear rotors. Service and Repair
5. Disconnect the eccentric shaft position sensor connector. Service and Repair
CAUTION:
- To cut the fuel injection and ignition, make sure the eccentric shaft position sensor connector is disconnected.
6. Measure the compression pressure using one of the following procedures:
a. Install the SST (49 F018 9A0C) to the trailing or leading side plug hole of the rotor housing.
b. Depress the accelerator pedal fully and crank for 7 s or more.
c. Read the compression and engine speed.
- Compression pressure
- Standard: 830 kPa {8.5 kgf-cm2, 120 psi} [250 rpm]
- Minimum: 680 kPa {6.9 kgf-cm2, 98.6 psi} [250 rpm]
- Standard difference in chambers: Within 150 kPa {1.5 kgf-cm2, 21.8psi}
- Standard difference in rotors: Within 100 kPa {1.0 kgf-cm2, 14.5 psi}
d. Perform the same procedure for the other rotor housing.
e. If the compression is at the minimum or less, or the difference in the chambers and difference in the rotors exceed the specifications, replace or overhaul.
CAUTION:
- If the engine speed when measuring compression differs from the standard, adjust according to the graph.
A
Standard compression pressure
B
Minimum compression pressure
7. Install the spark plugs. Service and Repair
8. Connect the eccentric shaft position sensor connector. Service and Repair
9. Install the engine cover. Service and Repair
Factory Service Tools
Use the Manual With the Right Hardware
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- β’ You smell fuel, burning insulation, or see smoke.
- β’ Brakes feel soft, pull hard to one side, or make grinding noises.
- β’ The engine overheats, stalls repeatedly, or misfires under load.
- β’ You are missing required tools, torque specs, or safe lifting equipment.
- β’ You are not confident in the next step or safety outcome.
