Megane II cranking short and not starting

[catalinadam25]

Hi chaps,

I have quite an odd problem with my Megane II, 2005, 1.9 TDci.
Last Monday the car didn't start in the morning after a cold night, all I had was short cranking and Injection fault after 3 failed start attempts.
I thought the battery went too low on power even though it's 3 months old. Jump started the car with a booster and it started straight away with the booster on, had a drivearound to charge the battery and left the car for the night. Next morning it started just fine, and I had no more problems starting until yesterday (Monday) when I got the same issue in the morning. After several failed attempts to start I left the car for the day in the parking lot. In the evening I checked the battery voltage and it was 12.35V which is not too low considering several start attempts I had in the morning. Started the car with the booster again (straight away as soon as the booster is connected) and left the car for the night. This morning I checked the battery voltage again, it was 12.6V, the car started just fine. Never had any other problems since I've changed the battery 3 months ago.
The alternator works fine, I got 14.5V with the engine running. The battery seems fine, it's holding power over night even when it's really cold outside (12.6V)
Is it possible to have a bad connection to the starter, a bad starter (sticky solenoid) or something else ?
I would appreciate your advice since I need the car to go to work and back home, that's 35 miles a day every day monday to friday.
And I make about 10-15 miles a day in the weekend as well.

Cheers

[joe12]

When the car does not start does it turn over slowly?

Even though the battery is showing a decent voltage when you check it I think it will probably be dipping down quite a bit when you are trying to start the car.

Is the battery the correct one for the car in regards to CCA (Cold Cranking Amps) I think your battery should be around 680 CCA.
A lot of cheaper batteries although the same physical size and same code number have a lower CCA which may not be a problem until you need to start the car in the colder weather.

You could also have a failing cell in the battery which isn't giving the correct amperage output, if the battery is only three months old I would go back to where you got it from and ask them to test it or swap it.

You could also have a parasitic drain that is draining the battery down a bit when the car isn't used every day, hence it starts great the next morning after being used the day before.

Google "parasitic drain"



Cheers.

[catalinadam25]

Hi,
Sorry for the late reply, the car turns just a bit when I press the start/stop switch, for a fraction, and then the lights on the dash go off.
The battery I bought is Exide Excell 71Ah 670CCA 12v.
I really don't think I have a parasitic drain since I started to have the same problem even if I drive the car every day, it does not start without the booster on the next morning.
I contacted the supplier and I am waiting for their reply.
I think most likely I have a failing cell in the battery as you said.

Cheers