big battery problems

[simonjr]

Hi,

Firstly - hope this is in the right forum.

I've had PAS problems - lights diming, having to turn the engine off and on etc. So I replaced the steering angle sensor over the weekend.

Anyway, all through this I have had problems with starting the car. Battery load check is fine (had it done professionally). Also had th green gunk around the negative battery post. Cleaned that all off and tightened everything up.

Anyway - this has now happened a few times.

Wife rang me this morning. Car won't start.

Leave it an hour, starts first time. Run it for a few minutes and turn it off. Try to start it again and it's dead.

The battery is only 6 months old and, as above, load check is ok. Charging seems ok - the guy at the mechanics said battery was basically fine. A bit low on the efficiency, but generally sound.

So, what on earth can this be. How can it not start. Start. Then not start again.

I'm running out of ideas on this now. I can't believe that something is draining the battery that quickly as why would it the start after an hour when apparantly the battery is flat?

Any help greatly appreciated - either here or via PM.

Maybe an earth?

help!! ;-(

Thanks in advance.

Simon

[ric04vrs]

nothing is draining the battery, as you say it starts sometimes, if it was drained it wouldn't start at all

i suggest all the large electrical connections around the engine bay are checked for corrosion and security, i'd say an earth lead is faulty

[Wardy]

I had something very similar with an Ibiza Mk4 PD130. Nearly drove me demented trying to solve it. Tried replacing the alternator, but eventually it was traced to faulty wiring in one of the main looms. So an earth issue might be the issue. Diagnosis was finally that the loom had been damaged during some previous servicing work. Took a lot of fault solving time by my local indy though...

But mine was very similar - I'd be able to do a full 3hr motorway trip, obviously with the battery charged as necessary during that trip. I would then stop at the end of it, and if I went to start up again within say 30 mins, it wouldn't start or could perhaps take 3+ attempts to catch

Good luck!!!

Steve

P.S. Here's my threads on the issue I had...

http://briskoda.net/ask-tech/starting-problem/69705

http://briskoda.net/ask-tech/fairly-major-electrics-issue/72074/ (this one has the final conclusion/solution, in the last post by me)

[allytech]

It could well be an earth problem, check the main earth from the batt and make sure it looks ok, could also be some wiring damage/corrosion in the main loom by the battery too, does the batt light ever come on when driving?

[thirty3]

I would try the dodgy earth also....

[simonjr]

really appreciate the input guys.

The "main" earth cable from the battery to the nut inside the engine bay looks fine. I tightened it up yesterday - to be honest I nearly threaded the nut tightening it up.

Is it possible to use the jump lead to go from the battery -'ve to, say, the -'ve on another car to bypass the earth and then see if the car starts. I'm a bit worried that this a hair-brain idea so thought I'd check before attempting.

[ric04vrs]

the earth has to be on your car, otherwise you wont have a complete circuit

[simonjr]

oops - of course ;-) you see this problem has got me going crackers now.

[skodakid]

You've probably got a duff battery or dodgy alternator. The green gunge is indicative of a discharged battery. Just because the battery is 6 month old and "professionals" say it is OKish doesnt mean its not duff.

Dimming lights = low system voltage = PAS will cut out when the voltage dips below a certain level. Its almost always because the battery cannot supply the necessary current. (You probably changed the angle sensor for nothing.)

Check the alternator charging voltage (14.1 - 14.5 volts, at 1500 rpm, all lights, heated rear window etc on). If thats OK, then its probably the battery (probably old stock or a cheapo brand or undersized battery)

[simonjr]

@skodakid.

You know what, I'm starting to think you are right.

Had a load test done and the alternator was throwing out 14.3 V with lights on etc.

I've had another look at the battery this morning and re-seated both + and - cables having cleaned posts and clamps. Everything looks right. I tightened up the bolts under the "battery hood/case thing" .

Had the same problem this morning. Car started (first turn, but not a confident first turn if you know what I mean). Let it run, turned it off - then it wont start again. Tried to turn a couple of times, but not enough juice.

I turned the lights on and tried to start it. Lights go our completely when key is turned. I think a new battery might be in order, as you say.

Other than that...god knows!!!

The only thing I can say about the battery is that the guys that tested it said it was a bit low on the efficiency. Something like 60% efficiency. Anybody know anything about battery efficiency? is that low enough to cause issues?

Yes - i think i did change the sensor without needing to. At least I could rule it out then, I guess.

Thanks in advance for any help.

Simon

[skodakid]

No such measurement as "battery efficiency" - just BS - probably meant his short circit tester only went to 60%, in which case your battery is duff.

Get a new battery - a major brand (I personally like Exide) - make sure its the largest size available for your model - and if you get a premium model they usually have a 3yr no quibble warranty, and usually last for at least 5 years, often 6+

MAKE SURE that the battery is new (ask for manufacture date) - batteries are stored dry (without acid). Batteries over 3 months old are usually returned to the manufacturer AFAIK.

[Wardy]

Obviously satisfy yourself that the battery is good for the job, but I have a suspicion that it's not the end of your troubles; see my linked posts.

But the best of luck with it and I sincerely hope that a new battery sorts your issue out.

Steve

[ap0gee1978]

As I mentioned in the other thread, it might be worth looking to see if any fault codes are stored for the immobiliser...

[viewer]

Perhaps worth checking earth by using wire with crocodile clips from terminal to (say) engine block.

[simonjr]

okey dokey - here's the update.

got a new battery yesterday. took the old one back and the guys changed it. It's not a great brand, but its cost me nothing to try it.

took it home, got it in (that containing nut is a rascal to get back on). Tightened it all up and...last turn of the spanner on the positive clamp and..sheered the damn nut ;-( Anyway by this time i was so p...ed off I just put it on as tight as I could with the other nut. Anyway, started first time and a few more times. You'd expect this anyway as it's a new/fully charged battery.

So after a night of wondering, I tried it again this morning and bingo firing up like a good 'un. I bought a new connector lead (had to go on the negative side and switch the bolt from -'ve to the positive side) and managed to get it all back to gether, nice and tight. Started up 5 times, even with the lights on.

I'm guessing, therefore, that the battery wasnt leaking through a dodgy earth (as it would have not started this morning).

Fingers crossed that this is now sorted out. Big thank-you to all of the help I received.

By the way my PAS light now just comes on for 1 second which is much better (seperate thread).

As you can tell, I'm quite excited ;-) I expect to be posting the problem is back again in a few days, but just in dreamland at the moment.

Thanks guys.

Simon

[Wardy]

Good stuff. Fingers crossed that sorts it

Steve

[MoggyTech]

Moral of the story, do the simple things first.

[Soot1e]

Legs crossed as well.

[simonjr]

Hi,

Just to wrap this saga up. The battery replacement seems to had done the trip. My wife has used the car a few timesover the last week. The car has also stood for a day or so.

Everything works fine. First time start etc. My wife comments that the car feels better than it ever did ;-)

So, thanks to everyone for the input ;-)

Simon

[DGW]

And thanks for the feedback, Simon. This thread could well help others with similar problems.