Grrrr! X5 not starting again!

Grrrr! X5 not starting again!

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Windymiller

Original Poster:

1,917 posts

187 months

Friday 3rd December 2010
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I'd been having starting issues with my X5 3.0D auto a few weeks back so took it to a few garages (non-BMW) who all diagnosed a knackered battery not holding a charge. I asked them to double check that it was the battery and not the alternator, and they all agreed it was the battery.

So I replaced it with the correct-sized Bosch battery, and all was well. However I noticed this morning that it seemed a touch sluggish to start, but put that down to the -7 temperature. However this evening it wouldn't start at all! Turned over once then the relays started clicking like mad. I got the jump leads out and it started first time.

I use the car every day, but my commute is only 2 miles each way, then I do about 50 miles over the weekend.

Any suggestions? Is there any way I can test the alternator myself, or for a power drain?

done by a diesel

81 posts

141 months

Friday 3rd December 2010
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put a multi meter on the battery when its not running. (about 12 to 12.5 volts) then get it started it then should read 13.5 to 14.5 volts with it running anything under 13.5 the alternator isn't charging would be my guess

Dimski

2,060 posts

146 months

Friday 3rd December 2010
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If the alternator wasn't producing a charge, then I don't think it would run for long with a flat battery.

So it still kinda sounds like the battery? confused

MJK 24

5,364 posts

183 months

Friday 3rd December 2010
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You could have a power drain somewhere.

Engine off, put a multimeter across the battery. Remove each fuse individually and see which one makes a difference. That's your problem.

Eggman

1,253 posts

158 months

Friday 3rd December 2010
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Windymiller said:
I got the jump leads out and it started first time.

I use the car every day, but my commute is only 2 miles each way, then I do about 50 miles over the weekend.
How long does it take you to drive the 2 miles? I suspect not long enough for the alternator to replace the charge you've taken out of the battery starting it, so it gets progressively discharged over the week. Starting a diesel is hard work in cold weather and batteries perform less well when they are cold.

Windymiller

Original Poster:

1,917 posts

187 months

Friday 3rd December 2010
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10 mins really. I know it's lazy but it's cold out there!

Eggman

1,253 posts

158 months

Friday 3rd December 2010
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I suggest taking a slightly longer route home for a few days to see if that's the problem.

Fire99

9,656 posts

176 months

Friday 3rd December 2010
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MJK 24 said:
You could have a power drain somewhere.

Engine off, put a multimeter across the battery. Remove each fuse individually and see which one makes a difference. That's your problem.
yes My Brother had a similar problem with an S-Type Jag. Was fine if the car wasn't left for more than a day but any longer and it would drain the battery.

I'd do exactly that, pulling individual fuses, relays etc and checking for changes.

Tallbut Buxomly

12,254 posts

163 months

Friday 3rd December 2010
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Fire99 said:
MJK 24 said:
You could have a power drain somewhere.

Engine off, put a multimeter across the battery. Remove each fuse individually and see which one makes a difference. That's your problem.
yes My Brother had a similar problem with an S-Type Jag. Was fine if the car wasn't left for more than a day but any longer and it would drain the battery.

I'd do exactly that, pulling individual fuses, relays etc and checking for changes.
This is your problem.

miniman

20,059 posts

209 months

Friday 3rd December 2010
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You'll be aware I'm sure that there's a small indicator light next to the gear lever which indicates the gear you're in. Assuming the car has been parked up for a few hours, go and look through the window (don't unlock the car!) and see if the light is lit. If it is, something is keeping the car "awake".

muckymotor

1,830 posts

168 months

Friday 3rd December 2010
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On a similar note, what should the cranking voltage be when checked across the battery terminals? My van has been struggling to start so I did a quick check and it's showing 9-9.5 volts.

Edited to add: after a search on Google the general opinion seems to be 9.6 volts and above.


Edited by muckymotor on Friday 3rd December 21:42

Bricol

140 posts

114 months

Friday 3rd December 2010
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As mentioned - you aren't putting back into the battery what you take out starting a big, cold diesel. And then add headlights, screen heaters, heaters, heated seats etc . . .

A quick google will reveal that the most common length of driving to put back into a battery what you take out in starting the car is around 30mins - and thats with some revs on to get the alternator energised and charging. Sat idling won't do much.

However - just in-case, ask your battery supplier to give it a quick test. Last winter I replaced an 8yr old battery in the integrale as it was starting to sound a little tired starting it on freezing mornings. Didn't take long for the new one to sound the same, and not start it if left for a week or so. Turned out the new battery had a duff cell - replace with no hassle under warranty.

Bri

Chicane-UK

3,860 posts

132 months

Friday 3rd December 2010
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Running into similar problems with my Corrado VR6. Fairly short commute which I have been cycling but because of some health issues over the last few weeks been using the car more. As the week goes on battery gets flatter and flatter cause of the heater, lights, etc.

Definitely start taking a longer detour home and you might find the battery holds out for the weekend for its longer charge!

GarryA

4,700 posts

111 months

Friday 3rd December 2010
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MJK 24 said:
You could have a power drain somewhere.

Engine off, put a multimeter across the battery. Remove each fuse individually and see which one makes a difference. That's your problem.
nono

Put the meter in line with the positive lead to measure current drain, then start removing fuses.

A battery with 0% life can read 11.9v on a meter, it will be around 12.6 when 100%.



Edited by GarryA on Friday 3rd December 21:14

joebongo

1,511 posts

122 months

Friday 3rd December 2010
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You can unlock the display to show you tests such as voltage and then check it when it runs. My E38 will show 13.4v I think when running at say 50mph and then down a bit when at idle, and with engine off it's about 12.2 or something.

If you do multimeter volts direct to the battery then it shows fractionally higher than looking using onboard tests as they systems take a bit of power.

To get down and dirty with the power drain if the above is ok:
Leave the access to the battery open (boot on E38, no idea on X5's)
Take out any bulbs which are on if it is the boot
Connect the multimeter in a line to the red terminal so it's in series with the car itself
Then lock the car.
Wait for that light next to the stick to go off and indicate it's really gone to sleep properly
Then look at the amps across the battery. Shouldn't be higher than 50ish milliamps.

If so, then repeat with the fuse panel accessible (windows open etc) and you can then start pulling fuses to see which circuit is causing the problem. From there it gets more specialised and I'd get onto bimmerboards or something to get the exact fix.

Edited by joebongo on Friday 3rd December 21:18

westom

22 posts

107 months

Saturday 4th December 2010
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Windymiller said:
I use the car every day, but my commute is only 2 miles each way, then I do about 50 miles over the weekend.

Any suggestions? Is there any way I can test the alternator myself, or for a power drain?
Two miles (ten minutes) is more than enough to recharge a battery. But some mechanics do not understand how the meter reads; how a meter finds and reports each failure.

You may have two different problems. The first is that only half an alternator is working. Or that it is not charging when RPMs are above idle.

As others noted, a normal battery is 12.6; 11.x volts when defective. However that measurement should be taken with engine off and high beams on. Loading is necessary so that a charged but defective battery does not appear good.

Same applies to checking charge voltages. 13 plus volts must exist when the engine is idling AND highbeams on, rear window defogger on, and heater fan on high. This voltage must also remains constant when the engine speed is raised above 1500 RPMs. A loose belt means charge voltage drops at higher RPMs. Some failed alternator diodes cause charge voltage drops when at idle (800 RPMs) under load. All measurements made with maximum loading (high beans, defogger, seat heaters).

A second problem would be a device that is constantly on - slowly discharging the battery. With the car off and battery terminal temporarily disconnected, use the meter in current mode to measure a current drawn from the battery. In current mode, the meter sits between battery and car's battery cable. First measure for 10+ amps. If at zero, then measure for lower currents. The consumption on a battery when everything is off (even doors close so that no interior light is on) should be about 0.1 amps (100 milliamps) or lower.

If meter is measuring 100 mA and you open a door, the large current drawn by interior lights might blow a fuse inside the meter. Be careful about unexpected loads when measuring current.

If that current too high, then remove fuses one at a time to find the function discharging that battery.

You definitely have a failure - no way around that. Too many mechanics want to keep replacing a battery rather than first find what is discharging or not properly recharging a battery.

DaveL86

847 posts

124 months

Saturday 4th December 2010
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MJK 24 said:
You could have a power drain somewhere.
That's where I would look.

My mum had a similar issue (non X5) which turned out to be a faulty fuel pump (in tank) which caused many hours a labour to try and diagnose.

I would take the car to either a good auto electrician or a good BMW specialist, wouldn't bother with main dealers unless you can guarantee a BMW master technician will be looking at your car, in most cases a technician (aka "part changer") will poke around for a couple of hours wasting your money then get the master technician to have a look.

While I mostly agree with the points made about short journeys in a large diesel is not the best idea, the car will/should be fitted with a sufficiently efficient alternator to charge the battery the same as any other car, it's not going to hurt taking an extra 5-10 mins each night to take a more scenic route home to see if it helps charge the battery but personally I can't see this being the issue.

GKP

15,099 posts

188 months

Saturday 4th December 2010
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Do X5s suffer from the final stage resistor problems that can plague early new-shape Range Rovers? (they share a lot of electrical hardware)

eliot

8,548 posts

201 months

Saturday 4th December 2010
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GKP said:
Do X5s suffer from the final stage resistor problems that can plague early new-shape Range Rovers? (they share a lot of electrical hardware)
Hedgehog is my thought to. Does your air blower sometimes get a mind of its own and start speeding up and slowing down?

podwin

652 posts

149 months

Saturday 4th December 2010
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i had this problem once, and the new battery was duff as already mentioned. It sent me down the wrong path suspecting a drain or duff alternator. So even though the battery is new it could still be the problem