Hi, I have a 54 Plate Punto Sport 1.2 8v, I think it is an MK2(face lift) or an MK3 I am not sure as the whole MK thing confuses me.

It has been doing a weird thing for a while, when I first get in the car and start the engine, the engine sounds like it is pulsating, kind of like I am revving it slightly (even though I am not) and the rev counter needle moves in time with this. I wouldn't really have paid much attention to the noise, but as it happens if my lights are on they 'pulsate' on and off slightly in time with the noise. The headlights, interior light and dials all do it. However once the car has been going for a bit, and I stop again, it is fine.

I am not really up on cars, but I wondered if it sounded to you guys if the battery is maybe on the way out?

Any help or advice appreciated.

Thanks

johnob said:

Hi, I have a 54 Plate Punto Sport 1.2 8v, I think it is an MK2(face lift) or an MK3 I am not sure as the whole MK thing confuses me.

It has been doing a weird thing for a while, when I first get in the car and start the engine, the engine sounds like it is pulsating, kind of like I am revving it slightly (even though I am not) and the rev counter needle moves in time with this. I wouldn't really have paid much attention to the noise, but as it happens if my lights are on they 'pulsate' on and off slightly in time with the noise. The headlights, interior light and dials all do it. However once the car has been going for a bit, and I stop again, it is fine.

I am not really up on cars, but I wondered if it sounded to you guys if the battery is maybe on the way out?

Any help or advice appreciated.

Thanks

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The revving slightly is the automatic clutch. (i.e. perfectly normal) it will turn itself off when the engine is warm enough.

And as for the lights pulsating, this will happen if you have alot of things running on the car at one time, (i.e. heater, aircon, lights, rear heated screen etc...), the alternator charges the battery acording to the ammount of revs the engine is running at (higher revs = greater charge created to recharge the battery) so when you have alot of draw on the circut (alot of things on) it struggles to keep a constant charging rate as the items that are running are taking the power.

Thanks for the reply that is really helpful, just one quick think, the car is not an automatic, but perhaps you mean something else when you say 'automatic clutch' ?

Thanks

johnob said:

Thanks for the reply that is really helpful, just one quick think, the car is not an automatic, but perhaps you mean something else when you say 'automatic clutch' ?

Thanks

Click to expand...

I think some one got confused with the 'Auto clutch' and didn't put it on paper clearly, so to speak.

I would have said it's normal but only in cold weather (2C etc) and my Panda does it for about 20 sec when cold.

Car's don't have auto chokes now! Because they're fuel injection, the fuel mix is adjusted accordingly to allow for the temp. It could just be your car sorting it's self out when cold.

Jon.

Sorry! :S i didnt mean clutch (i must have them on the brain )

I meant automatic choke, but as Most Easterly Panda's says there isnt an actaul choke on modern cars but the ecu adjusting the fuel/air ratio is the same principle