Misfires and an idle that rises and falls on the 1.6 16V (K4M): coils and the stepper motor

Engine / equipment

1.6 16V (K4M), petrol or LPG: Dacia Logan I, Logan MCV I, Sandero I and Duster I

Period mentioned

2006–2017

Symptoms

Backfiring and jerking: the engine misfires at certain revs because one or two coils stop sparking; or the idle rises and falls on its own.

Possible cause described

According to the owners who answer on DailyDriven, one Logan 1.6 16V lost two coils at different revs at 189,000 km, and on another the idle stepper motor made the engine “rev up and down on its own” at about 65,000 km; two other owners name the coils and the idle sensor as the parts that tend to fail. These are few owner reports, not statistics.

Check for the garage

Read the codes with an OBD reader to find which cylinder misfires and test by swapping the coil to another cylinder; check the spark plugs at the same time. If the idle hunts, clean or test the stepper motor.

Cost cited in the source

What DailyDriven owners paid: new coils and spark plugs, 324 lei (244 + 80); the stepper motor, about 500 lei. Amounts in lei from earlier years, not a current quote.A rough figure from the original database, not an up-to-date quote.

Sources from the original database