Parasitic drain possible alternator while sleeping?

[X5Sport]

With the IBS being in the main power charging circuitry which also includes the alternator, there may well be a possibility. I’m not discounting the alternator as a potential cause of this - though I’m puzzled as to which bit precisely.

These cars can be a nightmare to diagnose random/intermittent faults unless left strapped to test kit. Somewhere like a Bosch Autocentre may have the right code readers. Tricky of course under the current ‘limitations’. Annoyingly not everything creates a code, but it’s still probably worth doing. I think a main Dealer will charge around £100 for a diagnostic check.

I use the Carly system on all of mine (it uses a wireless dongle to Android/IOS tablets). You can also get hold of INPA and ISTA - you’ll need a computer to run them though. They’ll cost you about the same as a diagnostic check.

[Straycat_67]

With the IBS being in the main power charging circuitry which also includes the alternator, there may well be a possibility. I’m not discounting the alternator as a potential cause of this - though I’m puzzled as to which bit precisely.

These cars can be a nightmare to diagnose random/intermittent faults unless left strapped to test kit. Somewhere like a Bosch Autocentre may have the right code readers. Tricky of course under the current ‘limitations’. Annoyingly not everything creates a code, but it’s still probably worth doing. I think a main Dealer will charge around £100 for a diagnostic check.

I use the Carly system on all of mine (it uses a wireless dongle to Android/IOS tablets). You can also get hold of INPA and ISTA - you’ll need a computer to run them though. They’ll cost you about the same as a diagnostic check.

Really appreciate your input. I'm totally not car savvy so don't trust myself with self reader's etc....

Rather than say to an indy garage to change my alternator (£400+ supply/fit) and hope for the best, do you think i'm better off taking up the offer of my main dealer (who i sweet talked into letting me bring it down) for a 1hr diagnostics test @ £118?

Like I've mentioned, an auto electrician has narrowed down to the alternator area of the car based on the disconnection of the live under the bonnet, plus the fact the alternator was still hot 2+ hours after we turned off the car and the fact he had an extreme voltage run through his test cables whilst connected to the main rear battery. BUT, the car was going to sleep as it should whilst he was doing his tests, it's the random waking up that baffled him, however he did say in 30 yrs of working he's never had 2 sets on test cables burn out on him!

Dilemma's!!

[X5Sport]

As already said, the test cables were probably not rated for the 240A alternator output that these cars generate. It’s current that cooks cables, not voltage. If the test wires were thinner than the cable feeding the alternator, then that’s why they cooked! There’s a reason for the 12mm diameter power cable!

If the IBS says the battery is flat, then it will call maximum output from the alternator. These cars have serious electrical power draw due to the computers. My X6 draws over 60A doing nothing, hence the cars flattening their batteries in just 20 minutes with the ignition on and no engine.

Those of us (like me) who are electrical/electronics engineers know better than to stick a multimeter in circuit on a modern car unless it has a rating of 300A plus. We use current clamps that convert magnetic fields from the cable into a meter reading. No cooked wires or fritzed ammeters.

The alternator being hot 2 hours after use might be a clue, but if it’s running flat out charging the battery then it will be hot. Up to 240A is a lot of energy being generated and that means heat. Alternators are solid blocks of metal (iron and copper wire too, so they take a while to cool.

Do you know what voltages were being produced whilst the engine was running? You said 14V? Most E70s are fitted with AGM type batteries and charge at around 14.4V DC. The battery should show 12.8V fully charged and brand new - getting slightly lower with age or charge.

An Indy (especially a BMW one) should really have diagnostics kit too, so could read out the log. I know £118 sounds a lot, especially if they come back and say nothing shows up (we’ve all been there with modern cars, and it’s deeply frustrating), but it may be your only option at present. However, maybe there’s a Forum member close enough, even with Social Distancing, to help?

You said you don’t have Comfort Access, but do you have keyless ignition? Accidentally pressing the key buttons (such as in a pocket) will wake the car. I’ve noticed my 2-series doing it so the key it kept In an RFID wallet now. I’m just trying to eliminate all the simple options before money gets spent. It may be the alternator, but I’m just trying to think of anything else that could wake the car up. Bad door locks, bonnet catch, boot lid, anything plugged into a USB socket or 12V socket (those should power if with the car switched off), alarm system, ConnectedDrive (if used), non-standard kit plumbed into the electric somewhere?

I had a Road Angel connected to the glovebox USB port on the X6 and that caused an issue according to BMW. It was waking the car so I had to hard wire it into the 12V rather than use a USB cable.

[Straycat_67]

As already said, the test cables were probably not rated for the 240A alternator output that these cars generate. It’s current that cooks cables, not voltage. If the test wires were thinner than the cable feeding the alternator, then that’s why they cooked! There’s a reason for the 12mm diameter power cable!

If the IBS says the battery is flat, then it will call maximum output from the alternator. These cars have serious electrical power draw due to the computers. My X6 draws over 60A doing nothing, hence the cars flattening their batteries in just 20 minutes with the ignition on and no engine.

Those of us (like me) who are electrical/electronics engineers know better than to stick a multimeter in circuit on a modern car unless it has a rating of 300A plus. We use current clamps that convert magnetic fields from the cable into a meter reading. No cooked wires or fritzed ammeters.

The alternator being hot 2 hours after use might be a clue, but if it’s running flat out charging the battery then it will be hot. Up to 240A is a lot of energy being generated and that means heat. Alternators are solid blocks of metal (iron and copper wire too, so they take a while to cool.

Do you know what voltages were being produced whilst the engine was running? You said 14V? Most E70s are fitted with AGM type batteries and charge at around 14.4V DC. The battery should show 12.8V fully charged and brand new - getting slightly lower with age or charge.

An Indy (especially a BMW one) should really have diagnostics kit too, so could read out the log. I know £118 sounds a lot, especially if they come back and say nothing shows up (we’ve all been there with modern cars, and it’s deeply frustrating), but it may be your only option at present. However, maybe there’s a Forum member close enough, even with Social Distancing, to help?

You said you don’t have Comfort Access, but do you have keyless ignition? Accidentally pressing the key buttons (such as in a pocket) will wake the car. I’ve noticed my 2-series doing it so the key it kept In an RFID wallet now. I’m just trying to eliminate all the simple options before money gets spent. It may be the alternator, but I’m just trying to think of anything else that could wake the car up. Bad door locks, bonnet catch, boot lid, anything plugged into a USB socket or 12V socket (those should power if with the car switched off), alarm system, ConnectedDrive (if used), non-standard kit plumbed into the electric somewhere?

I had a Road Angel connected to the glovebox USB port on the X6 and that caused an issue according to BMW. It was waking the car so I had to hard wire it into the 12V rather than use a USB cable.

Thank you for your concise informed information and opinion.

It starts to go beyond me and it's such a shame I can't get you to speak directly with the auto electrician (apparently 30 yrs of experience and heaps of great reviews on yell.com), I'm concerned I'll give misleading information back to you on what he did to confirm either way. All I know is he gave the battery and alternator clean bills of health on charging and voltages, this was also the opinion of an indy garage (not great auto electrical fixes) and 2 emergency breakdown guys.
Maybe the auto elec underestimated the the drawing power of the X5 thus why his had cables and a multimeter fry, which does surprise me with his years of experience!

100% no fob would have set the car to wake up, keys are always 30+ feet away in a room a fair distance from the car, keys were'nt in pocket, made sure of that afetr the first time battery going dead. Basically the auto electrician came to conclusion after testing all components available that only a draw on 0.08 was happening once he put the car to sleep. I'm not sure he was aware of "IBS" so that's why I'm now confused and cautious about going head first into a alternator change. AS mentioned, the battery drain seems to have disappeared since the positive was disconnected underneath the bonnet, so presume it would have narrowed it down somewhat....??

With regard the alternator, understand the heat explanation (although I could touch the engine block as that was luke warm but alternator almost too hot to touch), but can I also say there is a hell of a lot of blackening on the copper coils of the alternator if that makes sense, is that ever a tell tale sign of an issue? The alternator is obviously working fine when the cars in motion as mentioned......

IF you or anyone else knows of someone competent with BMW's around my area (Wilmslow, SK9), love to get a recommend or assistance, just bad timing with the social distancing and closing down of most garages at the moment!

Thanks again for all your input and yes if no joy by the end of this week I'll have to grimace and take it to Halliwell Jones local BMW main dealer.

[Greydog]

I don't know if this helps but here goes.

I suffered a mystery drain with one of the Mercedes around 2004 the hot alternator was one symptom. The fix was a new voltage regulator, a diode in the regulator had failed allowing current to leak back. Mercedes had 3 goes and 3 fails the AA had 2 tries when stuck in hotel car parks and recommended new batteries each time. Once started the alternator charging rate was tip top.
Then with the car dead on the drive in the morning but the warm alternator was the first clue, disconnected the voltage regulator recharged the battery left overnight still charged next day. Reconnected the voltage regulator and within 10 mins a warm alternator. From memory the new regulator was about £60 and took a couple of hours to fit, problem fixed. One of my control engineers tested the original Voltage regulator and found the issue.

[X5Sport]

It could be a leak through the regulator to ground and that would create a hot spot. They’re usually removable and can be replaced by a service centre - or diy if you have the tools. You’ll need to identify the actual model fitted, or just ge5 a fully refurbed one put on. Way cheaper than new, especially if there’s a BMW Dealer involved!

[Wayfarer]

Relatively easy to check the voltage regulator and or diode block on an alternator with a decent multimeter, there is a lot of info on the web, although a bit surprised that a competent and experienced auto electrician didn't investigate this at the time, as it has always been one of the common failures on an anternator, and would give high current flows with the alternator connected and the engine off.

[Greydog]

Mercedes fitted 2 batteries and an alternator but for some reason used the original regulator? Both AA mechanics jump started the car then declared the alternator fine as it was providing a correct charging voltage, so blamed the battery and offered to sell me a new one which I declined as Mercedes had done that twice. Obviously none of them checked the regulator engine off.
It was only having a dead car in the morning but a warm back cover on the alternator that gave me the clue. Plus in those days being busy with business had it been a work day I would have called Mercedes or the AA to get it going again. I guess I was a tad lazy when it came to double checking what the "professionals" said lesson learned.

[Straycat_67]

3 days and live terminal reconnected under bonnet and ZERO drain!

Looks like the car has an untraceable gremlin which has a mind of it's own. Slightly annoying as I've got it booked into the main dealer tomorrow for a diagnostics check, I only hope that even though the drain issue that seems to have temporarily gone away can still show up on the diagnostics.

[X5Sport]

Sometimes, just sometimes these cars do suffer odd gremlins and BMW’s approach some years back was to fully disconnect the battery for up to an hour and then reconnect it. A bit like take 2 aspirin and call me in the morning, but just occasionally that is all it needs.

It makes fault finding on these wagons a lot harder than it both could and should be.

[Straycat_67]

Update:

After 1 hour at the main dealer for diagnostics they see a fault code coming up circulating around the GLOW PLUG CONTROL MODULE, however they need to go in to a 2nd hour to clarify. On Monday morning they will give me a costing on the control module, I get very very nervous IF in fact the part gets replaced and the problem still exists, what come back to I have?
Appreciate any feedback and thoughts?

Secondly, I have a seized DRIVERS FRONT CALIPER, Monday morning they will give me a price for a supply/fit. Appreciate what you guys believe is the likely price for this work in advance.

Cheers

[X5Sport]

Glow plug control on a car that old is very common and is frequently caused by failing glowplugs. It should be a relatively simple job but is fiddly on the E70 because of where the controller is located below the inlet manifold meaning disassembly required to get to it. The BERU made module is about £80, the BMW badged one will be more.

What often happens is the plugs start to fail and cause the controller to fail. Without the system working your DPF cannot regenerate and will eventually clog. You don’t want to get into that position as DPFs are expensive (BMW want about £1,500 plus fitting).

I had new plugs (6 off) and a new controller last year and the bill would have been about £450 at an Indy. If (like mine) the plugs stick and snap, then the bill (like mine) will be around £800. Parts are just over £150 all in so the rest was labour at £65/hr (+VAT).

I changed a front brake calliper last year for about £110 (there’s a £35 surcharge as well) and it took a couple of hours. Depending upon what else has been affected, you may need a new disc as well. That means new pads too. The brake system will need bleeding too. I changed calliper, both discs (one was heat damaged and warped) plus new pads and sensor.

With BMW you might be looking at the wrong side of £1k, a lot less at an Indy.

[Straycat_67]

Glow plug control on a car that old is very common and is frequently caused by failing glowplugs. It should be a relatively simple job but is fiddly on the E70 because of where the controller is located below the inlet manifold meaning disassembly required to get to it. The BERU made module is about £80, the BMW badged one will be more.

What often happens is the plugs start to fail and cause the controller to fail. Without the system working your DPF cannot regenerate and will eventually clog. You don’t want to get into that position as DPFs are expensive (BMW want about £1,500 plus fitting).

I had new plugs (6 off) and a new controller last year and the bill would have been about £450 at an Indy. If (like mine) the plugs stick and snap, then the bill (like mine) will be around £800. Parts are just over £150 all in so the rest was labour at £65/hr (+VAT).

I changed a front brake calliper last year for about £110 (there’s a £35 surcharge as well) and it took a couple of hours. Depending upon what else has been affected, you may need a new disc as well. That means new pads too. The brake system will need bleeding too. I changed calliper, both discs (one was heat damaged and warped) plus new pads and sensor.

With BMW you might be looking at the wrong side of £1k, a lot less at an Indy.

The hardest part is the skeptic in me, just because a code reader says it's the glow plug module (never had a problem with starting, only this recent parasitic drain) do I bite the bullet and get it replaced and PRESUME the parasitic drain goes away? Is there any questions I should pose to the main dealer Monday morning to help get reassurances to try an avoid throwing good money down the drain to find the drain is still there..... The dealer has not mentioned anything about faulty glow plugs, just a potential gp module and or attached cable, subject to further investigation.
My auto electrician is super skeptical just because a code reader brings up a particular fault code, he suggests to me that how do we know the fault code was not historic seeing as the car is 9 years old and I've only owned it for 4 years, does he have a point?
It's just so weird because like I said, the drain seemed to have disappeared for 3 days prior to taking it to the main dealer, so if the problem is now intermittent how can anyone 100% categorically confirm what the problem REALLY IS other than taking a code reader as gospel?

Re the caliper, it first reared it head 10 months ago, new pad, discs and caliper was apparently repaired (don't ask me lol ), but the problem has come back so will just get it replaced, whether I get my local indy to do it instead of main dealer is subject to what quote they come back with.

[X5Sport]

I understand your scepticism and after years of having difficult conversations, you are absolutely right to be. Part of the issue is they believe the code reader regardless. Too many BMW (and other) ‘technicians’ cannot work from first principles. Code readers can be wrong although it’s rare as it’s only reading what the car has recorded. I now have an understanding with the Master Tech at my Dealer so we can talk the same language as engineers.

If the dealer was doing the job properly they should clear the code and see if it returns. If it does then it’s real and still current.

You can always say to them that if it doesn’t clear the issue then you ain’t paying!

I didn’t bother servicing the sticky calliper on mine, I just swapped it out.

[Straycat_67]

I understand your scepticism and after years of having difficult conversations, you are absolutely right to be. Part of the issue is they believe the code reader regardless. Too many BMW (and other) ‘technicians’ cannot work from first principles. Code readers can be wrong although it’s rare as it’s only reading what the car has recorded. I now have an understanding with the Master Tech at my Dealer so we can talk the same language as engineers.

If the dealer was doing the job properly they should clear the code and see if it returns. If it does then it’s real and still current.

You can always say to them that if it doesn’t clear the issue then you ain’t paying!

I didn’t bother servicing the sticky calliper on mine, I just swapped it out.

Cheers! Monday morning I will ask 2 things:

1) Was the fault code cleared prior to the weekend and retested Monday morning to see if the fault code reappeared.
2) How do I know the fault code was not historic from years ago, not had a code check done since I purchased it (4 yrs ownership, purchased from this main dealer)