16 replies to this topic

[Bungle]

my mini hasnt been starting very well the last few times i have used it

the engine turns over slowly then stops turning over

the volt meter shows 11 volts with the engine not running and 14v when the engine is running

to start it i have to bump start it and after about a hours driving if i stop the engine it still wont start

i'm thinking starter motor am i right ?

[Turbo Nick]

battery dude, or a bad earth somewhere. charge up the battery overnight and check/clean the engine earth and the earth in the boot.

[Bounce]

Sorry, but i have to disagree. Bungle, as a fellow sparky you know that the volts your getting are ok. You wouldnt get them with a rubbish earth.

Id go starter motor myself.

[superted87]

simple first though gents. check evrything you can with regards your starter motor. Check the connections on the motor, wiring condition. Charge your battery up mate as said and give it some welly. If your battery cuts out after an hour of driving then check your alternator mate. ihad snags with mine and found out my plug had got all shitty and grimey on the Alternator. cleaned it up , problem solved . still dumbfounds me but worked.

ted

[Sprocket]

My money is on a bad earth despite whats been said, that is not wrong but inacurate

[Bungle]

i have checked all the earths and live connections and the battery is on charge over night

i have got it down to 1 of 2 things battery or starter (i think)

but how do you know what 1 has gone

[THedooBZ]

i had the same pronlem not long bac.
it turned out to be 2 wires shorting out on my loom.

worth having a look at the loom to make sure, have u done any work recently? as mine started after i disturbed the wiring when doing my head gasket. found the 2 offending wires taped em up and job done.

also 11volts when not running sounds a bit low, i takes around 10.5volts for you engine to crank and fire, and the voltage drop when you turn the key is gunna be more than 0.5volts.

as said charge your battery up, check the voltage after charge, then after a few days it should be the same if not and you know the battery is in good condition i would suspect a short.

when it had the problem i found i could drive for hours, get out of my car and then start it again a few mins later and it wouldnt. was quite puzzling when the battery was new and alternator was fine.

[stormduck]

turn the lights on when starting the car, if the lights start dimming when cranking over, it's the battery...if they stay bright, the battery's good.

[Sprocket]

turn the lights on when starting the car, if the lights start dimming when cranking over, it's the battery...if they stay bright, the battery's good.

Not necsisaraly

[icklemini]

Measure the voltage at the battery with an (accurate) voltmeter - if its showing 11v there then its the battery. It should be nearer 12.5v on a 'settled' battery (ie one that just hasnt been used and is charged up)

Check your engine earth strap to body - these often fail, fall off, get forgotten about...

TTFN,
Dave

[cooper_shaz]

What happens if you stick a set of jump leads on it when it is slow cranking ?
This may help although extra current through worn brushes in the motor will help it spin faster.
So as a true measure Connect a battery from another car up (use jump leads if it does not fit) see if it helps


It is a tough one there, but if in doubt replace the battery first as it is cheaper..
But from what you are saying and the voltages your getting it does sound like starter motor..

[Bungle]

its too cold to play minis today its still in the inlaws garage with the charger on the battery

i will see how it starts with a fully toped up battery some time over the week end

i'm a sparky so done all the easy tests and look at cables and joints

[mini-mad-dan]

just jumping in here is the starter motor is to blame then i have a 'home tested' starter in my garage, its a pre-engaged type, pm me if you need one

[Dan]

Have to agree with Dave and the others. 11v is too low really. Been on lots of short trips of less than 1/2 an hour lately? With the lights and heater and radio and heated screen and wipers on? 'because it sounds like daily driver winter battery syndrome, nothing wrong with the car just not running long enough to charge up fully. Other than that it's probably earths as above preventing it charging properly or the alternator.


Oh and on cars without hi-torq geared starters the lights will usually dim when you hit the switch, unless someone's invented some kind of bizarre ballasted headlamps that I don't know about.

[Bungle]

battery's been charging for 2 days now

mini started first time so its the battery gone duff (10 years old) or a current drane

i will see how long it stays charged up, might put my ammeter in the curcuit and see if theres a current drane (goes down to 0.001 A)