P0300critical severityPowertrain
Random/Multiple Cylinder Misfire Detected
on 1998 BMW 328is E36 2.8L I6 M52 ยท RWD
What this code means
The PCM has detected misfires occurring in multiple cylinders randomly. This is different from a single-cylinder misfire and often points to a system-wide issue.
Symptoms
- Check Engine Light (flashing if severe)
- Rough idle
- Vibration
- Loss of power
- Hesitation
- Poor fuel economy
- Possible catalyst damage
Common causes
- Vacuum leak
- Low fuel pressure
- Faulty spark plugs (all)
- Ignition coil pack failure
- EGR valve stuck open
- Low compression (multiple cylinders)
- Wiring harness issue
- MAF sensor problem
Diagnostic steps
- Check for vacuum leaks (smoke test)
- Test fuel pressure
- Inspect spark plugs
- Test ignition coils
- Check fuel injectors
- Test compression
- Check MAF sensor
- Monitor fuel trim values
Repair notes
Start with spark plugs and vacuum leaks. Flashing CEL means severe misfire - stop driving to protect catalytic converter.
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Other Powertrain codes on this vehicle
29CC
Misfire Cylinder 1
29CD
Misfire Cylinder 2
29CE
Misfire Cylinder 3
29CF
Misfire Cylinder 4
29D0
Misfire Cylinder 5
29D1
Misfire Cylinder 6
29D2
Misfire Cylinder 7
29E0
Lambda Additive/Idle Adaptation Limit, Bank 1
29E1
Lambda Additive/Idle Adaptation Limit, Bank 2
29E2
Lambda Multiplicative Part-Load Adaptation Limit, Bank 1