Grrrr! X5 not starting again!

[Windymiller]

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?

[Windymiller]

10 mins really. I know it's lazy but it's cold out there!

[Windymiller]

Well I'm guessing it must be the short journeys as, after getting a jump-start then taking it out for a good run, it started the next day (meaning the run must have charged it up) then again after another decent run. So to have gone from totally dead to this must mean it's both charging and holding it?

Or am I talking balls..

[Windymiller]

Unfortunately we live on the 7th floor of an apartment block, the car lives on -3, and the only power down there is for the lighting.

Bummer.

[Windymiller]

Cheers guys!

westom said:

Windymiller said:

So to have gone from totally dead to this must mean it's both charging and holding it?

Or only part of the charge circuit is working as clearly stated previously. Every reply is only wild speculation. You provided no numbers. So replies can only be speculation.

That two mile drive should be more than sufficient to recharge a battery if the entire charging system was operational.

Meanwhile a new battery should never be that discharged. So what caused the failure? It did not just happen magically and disappear magically. That or a trickle charger are both useless answers that pretend a failure does not exist.

Er, sorry, did I upset you?

[Windymiller]

Ah. From the above I'm guessing English isn't your first language. That's why I thought you were getting the arse.

Ta!

[Windymiller]

redtwin said:

Windymiller said:

Unfortunately we live on the 7th floor of an apartment block, the car lives on -3, and the only power down there is for the lighting.

Bummer.

Better invest in one of these then as you will be needing it on a regular basis. Pick them up for £30ish, it recharges from the mains in your flat.

You can also help things out by not using the climate control or heated seats etc while on the short journeys. Also when starting, switch ignition on until glow plug lamp goes out, then switch ignition off then back on again to give the glow plugs a "double shot" if you get my drift. Always seemed to make starting easier in the winter when I had my 330d.

Edited by redtwin on Monday 6th December 14:40

Where's that from mate? The one's I've seen don't seem good enough, only listing a 2.0 engine as the best it will start:

http://www.machinemart.co.uk/shop/product/details/...

[Windymiller]

Dave9 said:

kerry katona recently had problems with her x5

Haha. F*ck off

[Windymiller]

westom said:

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.

One thing I had thought though was that the built-in car-phone (Motorola V50) is always plugged into the armrest, and never used, but possibly always on charge? So I've unplugged that to see...

Last night, I took some measurements with my multi-meter:

—no draw, engine off, 12.55v
—no draw, engine on, 13.75v
—draw (blower, lights, nav), engine on, 13.75v

I also checked what the current draw is when she's totally powered down (sleep mode):



Suppose all I can do now is see if removing the phone has cured it?

[Windymiller]

Well, after all that it turned out to be the bloody built-in phone! Seems my girlfriend had a play with it one day and turned it on, so it's been powering itself off the car ever since I thing. Removed the phone plus relevant fuses and (touch wood) it's been fine ever since.

Anyone need a new X5 battery?

[Windymiller]

I had every intention of doing so this morning... then I woke up and there was snow everywhere!

I'm sure it's not safe/possible to cycle in snow