Starter engagement

Q

On occasions when starting my 2007 Fiat Punto Grande Dynamic 1.2 8v, it was evident the starter pinion wasn’t disengaging as quickly as it should, as I could hear it fouling the flywheel ring gear as the engine fired. There was never any problem starting the engine and the pinion always seemed to engage correctly.

I decided to fit a new starter motor and this cured the problem, but on a few occasions the pinion is not engaging on first turn of the key. It can be heard just about making contact with the flywheel ring gear, but not enough to turn the engine over. On trying a second time, it starts with no problem.

The battery is in good order and I have double-checked all connections, including cleaning up the earths. I have removed the starter again and lightly lubricated the pinion shaft, but the problem persists, occurring completely at random and no more than once in a 10-day period. I have ruled out the flywheel ring gear as the problem because the original starter motor always engaged without issue. Am I missing something or is the replacement starter motor faulty?

Keith Chester

A

Although you have lightly lubricated the pinion shaft, this is not advisable as any lubricant on the shaft will attract clutch dust particles and cause further problems. It is always recommended that the pinion shaft should be dry.

Provided the ring gear is perfect as you say, then there are two possible scenarios. The first is that the pinion has been made with a slight imperfection that is causing the problem. If this is the case, the starter should be replaced under the warranty as it is faulty.

The other possibility is that the starter is not sitting correctly. In this case, loosening it off and attempting to reposition it slightly may achieve the desired result. I would attend to the problem as soon as possible, because if the pinion is engaging poorly with the ring gear then damage of the ring gear may result.