Car seems it won't start but eventually does

Question

My car is an Opel Corsa B.

Recently, it started having trouble to start.

When I turn on the key, the car behaves like the battery is empty (slow cranking -low choking sound- of the engine and the lights become much dimmer than usual) but after a few seconds the cranking sound becomes gradually normal (louder) and the car eventually starts.

It still starts from the first try though but it always seems like the battery is empty at first.

I have been told it is a dying battery, but then why would it gradually start, wouldn't be other way around, gradually coming to a stop ?

Answer 1

This could well be due to dirty connections on the battery terminals.

Disconnect the battery connectors and clean the battery posts and connectors. Wire wool or wet and dry abrasive paper should do the job. It you still have problems, it could be the connection from the battery negative to the body, you may need to clean that connection too. Ideally you should clean the large connection to the starter motor and the engine earth strap to make sure you have the best possible connection. To avoid a fire, make sure you have the battery disconnected while cleaning all of the connections.

The reason why this could be happening is due to a bad connection causing a voltage drop across the connection. The connection is probably warming up as you try to start the engine. Expansion in the connector due to heat then makes a better connection and the motor speed increases.

Answer 2

Load testing the battery gives clear idea of any intermittent issues and issues related to cells surface charge. If under warranty replacement will be almost free of cost.

By the way, as suggested in the answer by @handyhowie, connectors are corroded and are causing contact error. Use of WD-40 (Water Displacement-40) would definitely help. Spray it at all the places from the battery terminals and starter terminals, to the points of ground in the engine compartment, ignition key switch and dashboard grounds (usually bunch of blackwires connected to car body) near driver side and passenger side.

Nonetheless, if this step doesn't solve it, then your starter solenoid switch and starter motor needs cleaning/overhauling. The carbon brush when are worn also initially cause this sluggish movement of the starter motor. The good quality carbon brush set comes as an assembly in the aftermarket, for around $5-$12, depending upon the starter OEM. You can check the oem catalog/part number for your car starter at www.boodmo.com and/or amazon.com or other automobile online sellers websites.

HTH. Best of luck. Best regards.