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MG MGF Technical - Possible battery issue?

Hello All!

Ive noticed some strange problems with the Trophy and not sure where to begin

The battery seems to drain really quickly.. If I forget to disconnect the iPod and leave the car overnight it just about starts the next morning, or when fitted the K&N and had the doors / boot open for length of time (just over an hour).

Also Ive noticed after driving into work stopping the car getting out to unlock car-park gates the car is hard to start or starts and dies after a couple of feet.

Also when the car went through the mot recently - it was difficult to start after stop engine - do check .. start engine, drive to next test .. everytime the car was difficult to start. I thought this was maybe due to the the engine being started and stopped too frequently.

Any thoughts?

Cheers, Neal
N McNamara

Hi Neal,

Is the hot re-starting problem that the engine turns slowly and doesn't fire straightaway? If so then the battery is prime suspect, not able to turn the engine and produce a strong spark at the same time.

I've seen batteries still showing the 'good condition' indicator having degraded to this level, so don't put too much faith in that.

Mike Hankin

Hi Mike .. thanks - that's a much better way of describing it than mine - hot engine doesn't fire straightaway.

Very strange, as I've left the car at the airport using airport transfers tonbridge for 7days - and it fires on the first click .. leave the doors open or iPod connected and the battery is gone, or very nearly gone.

Another thing I've noticed is that when I pressed the brake pedal the oddometer dims :(

How much is a new battery? I'm assuming that's an easy job..

Thanks, Neal
N McNamara

Pretty easy to swap a battery. Halfrauds sell them for about 30-40 quid for a decent one. If you've got a MPi with EPAS, buy the larger batter for the VVC (the battery guide in store is misleading)
Rob Bell

Hmm, a kaput battery I wouldn't expect to be willing after just resting for 7 days...

A new battery is probably around 40, with winter coming I'd be tempted to replace it anyway and see what effect that has. Swapping them is very easy, the clamping plate needs a 10mm socket and a longish extension, but then it's just a 13mm IIRC spanner on the terminal clamps.
Mike Hankin

Hi N mc namara the oddemeter dims i have have on mgf 2001 model it this a thing that the f suffers from taken power from the battery

darren jeffery

Personally I'd be worried about the alternator - with the engine running is there 14.5->15.5 volts on the battery terminals, if not then you have an alternator problem. A new battery may hide this for a few months, which puts us neatly in freezing fog and christmas!
Will Munns

Will's advice I think is good - alternator might be the culprit, or possibly the rectifier located within the unit (converts the generated AC into usable DC), which sadly isn't serviceable so a new alternator seems to be the only cure. Shouldn't be difficult to get it checked out at an auto-electrical workshop, agreed a new battery may only temporarily mask the problem.

If your battery has been cooked to the point it couldn't start the engine, I'd still budget for a new one - never completely reliable once they've hit rock bottom...
Mike Hankin

This thread was discussed between 27/09/2005 and 30/09/2005

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