What does code P0305 mean on a Mercedes-Benz and is it safe to drive?
P0305: Cylinder 5 Misfire Detected. Here's what it means on your Mercedes-Benz, what usually causes it, what repairs typically cost, and how safe it is to keep driving.
What this code means
Misfire on cylinder 5—present on V6, V8, and inline-5 engines only. On V6 engines, cylinder 5 is sometimes harder to access; factor labor into repair estimates.
Common causes for your Mercedes-Benz
- Fouled spark plug
- Failed ignition coil
- Leaking or clogged injector
- Low compression from valve or ring wear
Symptoms
- Check Engine Light
- Engine shaking or rough idle
- Power loss under acceleration
Typical fixes
- Replace spark plug and coil on cylinder 5
- Test and replace injector if needed
- Compression and leak-down test
Repair cost range
For a Mercedes-Benz, repairs for P0305 often fall between $150 and $1000, depending on the cause and whether you use OEM or aftermarket parts. Labor rates vary by location.
Known issues on Mercedes-Benz
Mercedes M272 P0305 on rear-bank cylinder 5 typically means a failed ignition coil. If balance shaft timing is confirmed good, replace the coil cassette for the rear bank. On the M272, replacing the rear-bank cassette requires intake manifold removal.
Most commonly affected models