Metering Oil Pump Malfunction (Mazda)
What does P1680 mean?
The P1680 code means the vehicle's onboard diagnostic system has detected: Metering Oil Pump Malfunction (Mazda). This is a critical severity code.
Common Symptoms
- Check Engine Light on
- Engine knocking or unusual noise
- Blue or white exhaust smoke
- Loss of engine power
- Engine overheating
Probable Causes (Ranked by Likelihood)
- Failed metering oil pump Very High
- Clogged oil metering lines High
- Low engine oil level Moderate
- ECU metering pump driver failure Low
Step-by-Step Diagnostic Procedure
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Check engine oil level immediately. Rotary engines depend on oil injection for rotor seal lubrication.
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Inspect metering oil pump lines for kinks, cracks, or blockage.
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Test metering oil pump electrical connector for proper voltage during engine operation.
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Measure metering oil pump flow rate per Mazda specifications.
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If the pump has failed, do not run the engine as this can cause catastrophic rotor housing damage.
Frequently Asked Questions
Why is this code critical on a rotary engine?
The metering oil pump injects oil directly onto the rotor apex seals for lubrication. Without this oil, the seals will score the rotor housing, requiring a full engine rebuild.
Can I premix oil in the fuel as a temporary fix?
Some RX-8 owners premix 2-stroke oil in the fuel as a supplement, but this is not a substitute for a functioning metering oil pump.
Is this related to the RX-8 oil consumption issue?
Yes. RX-8 rotary engines consume oil by design through the metering system. If the pump fails, the engine loses this critical lubrication.