Engine & fuel system
4 documented faults — symptoms, causes and workshop fixes.
Engine malfunction indicator lamp (MIL) illuminated
Symptoms
Engine runs in limp home mode. Trouble code stored: P0440.
Cause
Evaporative emission (EVAP) canister purge valve faulty.
Repair
- Fit new evaporative emission (EVAP) canister purge valve.
Parts7 parts
| Part | Part number | Qty |
|---|---|---|
| EVAP valve | LF66-20-360K | 3 (→2005) |
| EVAP valve | L32D-20-360D | 3 (2006→) |
| EVAP valve | L391-18-740C | 6 (→2005) |
| EVAP valve | L3P9-18-740B | 6 (2006→) |
| EVAP valve | LFG1-18-741B | MX-5 |
| EVAP valve | L3P5-20-360B | 5 |
| EVAP valve | L33L-18-740B | CX-7 |
Data: Motorwise Workshop. Bulletin 1.
Erratic idle. No trouble codes stored in fault memory
Throttle body contaminated with carbon deposits. Fix: clean and lubricate.
Overview
- Affects
- All models.
- Remedy
- Clean & lubricate
Symptoms
Engine stalls at idle. No trouble codes stored in fault memory. Engine stalls/cuts out when vehicle comes to a standstill. No trouble codes stored in fault memory.
Repair steps
- Remove throttle body.
- Clean carbon deposits from throttle body.
- Refit throttle body. Renew throttle body gasket.
- Initialise throttle control unit as follows: Switch ignition ON. Wait 1 minute. Switch ignition OFF. Wait 1 minute. Start engine. Allow engine to idle. Ensure all electrical equipment switched OFF. Allow engine to reach normal operating temperature. Check that idle speed remains within specification.
Parts
| Part | Part number | Qty |
|---|---|---|
| Cleaning spray | 000-77-A86 | 1 |
| Throttle body gasket | L3K9-13-655 | 1 |
Data: Motorwise Workshop. Bulletin 2.
Excessive noise from camshaft position (CMP) actuator, especially when starting from cold
Camshaft position (CMP) actuator locking pin not fully engaging. Fix: fit a modified part.
Overview
- Affects
- All models, →04/07.
- Remedy
- Fit modified part
Repair steps
- Fit modified camshaft position (CMP) actuator.
- Change engine oil.
- Start engine. Allow engine to idle for a minimum of 5 minutes.
- Check high-pressure fuel pump for leaks.
- Switch ignition OFF.
- Allow engine to cool.
- Change engine oil and filter.
Parts
| Part | Part number | Qty |
|---|---|---|
| Camshaft position (CMP) actuator | L3K9-12-4X0B | 1 |
| Washer | L3K9-12-4X0B | 2 |
| Engine oil | 0000-77-5W30-QT | 11,4 litres |
| Engine oil filter | L321-14-302-9U | 1 |
| Bolt | LF01-11-406 | 1 |
| Engine oil sump drain plug | 9XG0-99-667L | 1 |
Data: Motorwise Workshop. Bulletin 3.
Oil leak from rear differential
Unsatisfactory design of rear differential breather valve causing pressure build up in rear differential. Fix: fit a modified part.
Overview
- Affects
- All models with four wheel drive, →07/11.
- Remedy
- Fit modified part
Repair steps
- Fit new driveshaft oil seals.
- Fit modified rear differential breather valve.
- Fit protective boot to rear differential breather valve. Ensure protective boot ventilation hole faces rear of vehicle.
Parts
| Part | Part number | Qty |
|---|---|---|
| Rear differential breather valve | B39M 26 060 | 1 |
| Protective boot | B39M 27 763 | 1 |
| Driveshaft oil seal | M0A7 27 238A | 2 |
Data: Motorwise Workshop. Bulletin 6.
Electrical & ignition
1 documented fault — symptoms, causes and workshop fixes.
Failure of left or right headlamp
Overview
- Affects
- All models with gas discharge headlamps.
- Remedy
- Fit new part
Cause
Headlamp igniter unit not fitted correctly causing poor connection.
Repair
- Ensure headlamp igniter unit is disconnected from power supply.
- Fit new headlamp bulb and headlamp igniter unit. Turn headlamp igniter unit fully clockwise until it locks into position.
Data: Motorwise Workshop. Bulletin 4.
Brakes
1 documented fault — symptoms, causes and workshop fixes.
Groaning noise from rear brakes when brakes applied
Vibration between brake pads and discs. Fix: fit a modified part.
Overview
- Affects
- All models.
- Remedy
- Fit modified part
Repair steps
- Remove rear brake pads.
- Clean mating surfaces of brake caliper and carrier.
- Apply grease to contact surfaces of rear brake pad back plates.
- Fit modified rear brake pads. Ensure brake pad anti-squeal shims are fitted.
Data: Motorwise Workshop. Bulletin 5.
Glossary
Technical terms used in this guide.
- Trouble Codes
- Standardised fault codes stored by the engine control module, read with a diagnostic tool
- CMP
- Camshaft position — a sensor that tells the engine control module where the camshaft is
- Actuator
- A motor or solenoid that moves a mechanical part on command
- Caliper
- The part that squeezes the brake pads onto the disc
- Driveshaft
- The shaft that takes drive from the differential out to a wheel
- Fault Memory
- The list of stored trouble codes in a control module
- Limp Home
- A protective mode that limits power so the vehicle can be driven to a workshop
- Trouble Code
- A standardised fault code stored by a control module, read with a diagnostic tool
- Initialise
- A workshop procedure that teaches a new module or system its starting values
Frequently asked questions
What are the common faults with the Mazda CX-7 2.3?
This guide contains six workshop bulletins for the Mazda CX-7 2.3. Of these, four concern the engine and fuel system and one the electrical and ignition. Symptoms, causes, repair steps and part numbers are shown where supplied.
Does every Mazda CX-7 2.3 have these faults?
No. These are patterns documented across the model by workshops, not predictions for an individual vehicle. Where a fault applies only to certain vehicles or VIN ranges, that is listed with the fault.
Can I check for Mazda CX-7 2.3 faults myself?
Many of them. The documented symptoms can be seen, heard or felt during a test drive.