[id2008]

My wife´s been having a few problems with her Renault megane scenic (aka french pos)
anyways, for some strange reason if the car isn´t moved for more than a day she´ll struggle to get it on. After 2 days only way to get it on is by jump-starting it, even though the battery seems fine and is giving ignition?
Any Ideas on what the problem could be ?

[Sensbachtal]

From what you described, it sounds like the battery. I just replaced mine a couple days ago because it was bad. I could jump start it, and drive it anywhere, but if I waited more than a few hours, it wouldn't start again.

What makes you think the battery is good?

[Farson]

How old is the battery? They can appear to be fully charged but be unable to supply the required cranking current/voltage when they get old. Seems to be getting worse and worse with more modern batteries [cursing]

[id2008]

From what you described, it sounds like the battery. I just replaced mine a couple days ago because it was bad. I could jump start it, and drive it anywhere, but if I waited more than a few hours, it wouldn't start again.

What makes you think the battery is good?

well first of all because the battery is relatively new and second off i can´t hear or feel any difference between ignition when just using the battery that´s already in the car and jump starting it via a second car.

[viagracheapest]

you may have a power drain somewhere that's taking the battery below the threshold to start it.

the most power draw when you turn the key is when the engine is first flicked.

you need to get a tester, and check the cranking voltage,against the battery non loaded voltage.

if it drops below 10v it will need charging and or a new battery (even new batteries can be duff depends how long they've been in storage since initial charge)

a cheap multimeter or alternator/battery state checker between the negative on the battery and the positive on the starter motor terminal.

[exchpaypalgold]

well first of all because the battery is relatively new and second off i can´t hear or feel any difference between ignition when just using the battery that´s already in the car and jump starting it via a second car.

How much is "relatively new"?
2 years was all it took for my Motorcraft battery to die.

[dolaBeetCeage]

well first of all because the battery is relatively new and second off i can´t hear or feel any difference between ignition when just using the battery that´s already in the car and jump starting it via a second car.

so after two days the engine just cranks and cranks and cranks but wont fire up?

or does it go click click click

[movlabc]

I'd say it is the battery as well. I just had a similar problem with my car. The battery was only a year old and would only hold enough charge for about a day then it wouldn't have enough to crank the engine over and had to be jumped. Replaced the battery with a "heavy duty" one that has quite a bit more CCA (Cold Cranking Amps) than the old one. Battery is having no problems lasting for a week without running.

Maybe check the water levels in the battery if you can first. They might be low.

Of course it could be the alternator, does she have any problems when running with the lights on?

[arriftell]

Might be the battery, or it might be a short in the wiring.

Did you recently have a new stereo put in the car or something that would have affected the wiring?

[Maymayfor]

My wife´s been having a few problems with her Renault megane scenic (aka french pos)
anyways, for some strange reason if the car isn´t moved for more than a day she´ll struggle to get it on. After 2 days only way to get it on is by jump-starting it, even though the battery seems fine and is giving ignition?
Any Ideas on what the problem could be ?

my friend check the alternator output. as well as a load test on the battery. how old is hte battery if i may ask. ive wanted to import a renault into the us. one of the older ones. i had seen one locally had a bumper sticker on it it said."it may be slow, it may be ugly, but it IS in front of you"

[Maymayfor]

How much is "relatively new"?
2 years was all it took for my Motorcraft battery to die.

aye ive gotten 5 years out of my police car battery. course when i park the car for winter. i pulled the battery out and stored it inside on trickle. but when it died, it died HARD. climate has alot to do with how long a battery lasts

[id2008]

so after two days the engine just cranks and cranks and cranks but wont fire up?

or does it go click click click

It cranks and cranks and cranks
it sounds totaly normal, it just won´t ignite.

edit: btw the battery is just a bit over 6 months old

[rxnixoncom]

It cranks and cranks and cranks
it sounds totaly normal, it just won´t ignite.

edit: btw the battery is just a bit over 6 months old

Doesn't matter, doesn't hurt to check it as others have suggested. If you find that it's the culprit; there you go. If not, move on to the next likely suspect.

[dolaBeetCeage]

It cranks and cranks and cranks
it sounds totaly normal, it just won´t ignite.

edit: btw the battery is just a bit over 6 months old

then i doubt it's the battery, but with a jump start working... i dunno, some sort of electrical gremlin

[Ebjjrxrd]

if you have a friend with a good car battery, swap it out and try that and see if the issue is solved.
Im kind of lost for ideas, Maybe when the car has sat for 2 days, the voltage is low enough in the battery to keep the car from starting?

Follow me here and let me explain a little further.

When the car is driven constantly, the alternator keeps the battery voltages at peak. When the car sits unused for 2 days or so, maybe the voltage is droping. But if it is strong enough to turn the motor over, shouldnt it start? Well, maybe the starter puts to much of a draw on the battery and in turn keeps the actual ignition system from getting its needed voltage to start.

That or maybe you have a loose connection on your battery post. Are all of your connections to your battery posts through one solid solder joint on the connector, or are the wires clamped in the battery post connector? if its the latter, it might actually have a loose or poor connection in that.

[gariharlj]

What about spark plugs? just an idea.