Hello fellow owners,
First of all, I'd like to say that I appreciate this community, and have already done an extensive search to try to narrow down the possibilities on what could be the cause of the issue I'm experiencing.
I'm currently having an issue with my 2004 BMW Z4 3.0i. As of a couple weeks ago, it started to really struggle to turn over, and then it failed to turn over altogether, leaving me with just a single click when I turned the key to the start position as I normally would to start it. I managed to push start it and get it into the shop, where I figured I may as well swap the battery out (it was around 7 years old at this point), and hoped that would fix the issue. It didn't, so then I turned to what I would think to be the next likely culprit, the starter. After purchasing a starter, and spending several hours replacing it myself, the car turned over and has been starting perfectly and running just fine for the past week and a half or so.
Today, after leaving work, I went to start the car and was met with the same single click from before. I'm really stumped here guys. I would assume the alternator is fine, as the battery still is being charged and hasn't gone flat on me, but the starter doesn't even engage! There's just a single click, not even a struggle!
To summarize, I have already replaced the battery and the starter, and have just gone through some of the more obvious fuses (immobilizer, ignition starter switch, clutch switch, dash lights, EWS system, etc), and all of the fuses look perfectly fine. I downloaded the BMW INPA software today (v 5.0.1), and while a good deal of it is in German I am more than capable of translating via google so I will give that a shot tomorrow. Does anyone have any suggestions on what to try next?
Access and post back with INPA error codes displayed.
Are you really sure alternator is charging the battery properly. I would suggest that you have it checked out just to confirm that it isn’t a problem. Test battery voltage cold... check voltage output when running at idle... rev engine and check voltage out put at 3000 rpm. Voltage regulator could need replacing.
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Addendum.... I’m presuming with my reply you are able to charge battery/or are able to jump start the start car.
You have described a classic scenario for a bad voltage regulator/alternator and you state you “assume” the alternator is charging the battery.
FWIW... Cold voltage on a new battery is somewhere around 12.6V....
My two cents worth having been there done that....
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Thanks for the replies, I will go head and test the alternator and monitor voltage tonight when I get back from work.
One thing that I think might be important is yesterday when I was on the highway at a rapid pace, I experienced having multiple yellow warning flights flicker on, ABS, brake, DSC, steering, and then the flickered intermittently in and out for a few minutes, and then back off and didn’t return. Classic alternator/voltage regulator issues?
If your alternator isnt charging battery and your voltage drops it could cause the flashing lights.
I would also agree that it might be alternator too along with battery. Not really sure starter needed to be replaced
Alright I have an update,
Tonight I attempted to jump start the car with my brothers car, and no luck, just the same turn of the key and a single click. I then push started the car and ran it around town for about an hour to let the battery get some charge.
I then bought a multimeter and took some measurements of the voltage with the car on and then with the car off.
With the car running (~2,000 rpm), the voltage reads ~13.79 Volts, which as I understand it is right around what it should read.
With the car turned off (and allowed to sit for 20 minutes) the voltage reads 12.39 Volts. This is with the trunk light and dome light on (as in when you open the trunk they come on). I’ll go ahead and test the battery again tomorrow morning and late afternoon to see if there is any difference. Any thoughts from those of you with more experience?
I went in, it's a little tricky using google translate from German, but I was able to pull the following codes. Not sure if it's relevant to note that the starter seemingly went bad, was replaced, and has run fine for the past two weeks or so until I ran into the same issue as before, and I've been push starting it (only when necessary, 2-3 times maybe) to get it from place to place when I absolutely have to.
These two pages were pulled from under the Engine (M54) selection from the main screen, and then under the Error tab (F4), and then under the Detail screen (F2).
Error Codes Page 1.PNGError Codes Page 2.PNG
Last edited by TitanUcheze; 07-24-2018 at 10:21 PM.
I would start with the engine ground if I were you. At first you can try to bypass it with a starting cable, just connect the engine block to any ground on the chassis. Try to start then.
Martin Voigts
BMW cars indy and locksmith
1997 E36 318iS Sierrarot
2012 Ford Mondeo
There is an English version of INPA.... that provides the majority of the upper levels of INPA in English....including error/fault pages.
Did you observe the voltage output from idle to higher rpm? If the voltage output remained relatively constant then the regulator is working within designed parameters. However if the voltage “tracks” (increases) as the rpms increase then the voltage regulator is faulty. I would also do the rpm test from idle to 3000.
Voltage 20 minutes after running isn’t “cold” voltage. Cold voltage is next morning prior to starting when bad/weak battery etc has had time time to settle down to a static state.
Having to push start the car after having measured 12.4V on a warm battery the night before still points to battery/regulator issues.
BTW ... you can have codes showing in INPA for various things that don’t effect driving of car... Random faults(windows/window spray nozzle .... and my favorite... oil sensor open circuit..not present now)
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Thanks for the reply guys, I will do the rev test again tonight but when I got home last night and the car was running I did have my brother hop in and rev from idle to around 2000 rpms, and then up to around 5000 rpms, there was some small variance but if anything the voltage dropped slightly. I will measure the voltage again tonight (as it has sat for around 18 hours by that point) and will report back with the value, and then do the revving again to get some concrete numbers for how the voltage of the battery reacts.
Thanks for the code info, I did a quick search and that's what it seemed to come to, most of them being "implausible" / ignore-able for this issue.
If the battery voltage is still within range when I get home (around 12.4 - 12.6V) and as I tested last night it was at 13.79V when running at idle, do you mean to say that the battery and alternator cannot be ruled out as potential issues causing it not to start? Wouldn't it have no issue starting if the alternator and battery voltage appear to be at the appropriate levels?
Or do you mean to say that the voltage regulator (even with the battery having the necessary voltage) could prevent the necessary amount from getting to the starter?
- - - Updated - - -
Thanks Fx, I will attempt that when I get home after work, am I understanding correctly that by using jump leads and connecting the engine block to the chassis and attempting to start I am in effect grounding the starter? Or is there a separate ground specifically for the engine block that could have gone bad here?
Also, would the engine still push start manually if the engine was not grounded properly?
These should have nothing to do with the starter.
One more thing to check is the EWS system again. This time not the fuses but the input and output from the ignition switch and to the starter. The easiest way to test is to unplug the ews connector and on it, there are two large pins. If you take a 30A fuse, it will be a direct fit to these pins. Leave the EWS unplugged and the fuse in the connector instead. Try to start. If the starter works fine now, thw ews is to be replaced or the relay in the ews is to be bridged/replaced. If the situation does not change, measure the voltage on the fuse in the connector. How much would the voltmeter say?
Martin Voigts
BMW cars indy and locksmith
1997 E36 318iS Sierrarot
2012 Ford Mondeo
I agree that you might have a bad ground cable engine/frame....
I’m also curious if the replacement battery was new or used.... that said ... you haven’t stated what the “cold” morning voltage of the battery was prior to starting car. I would have the battery checked out to confirm that it is good.
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The engine grounding strap forms part of the power circuit/path for starter/battery. Without the grounding strap the circuit is broken. A degraded/corroded/frayed strap will eventually lack the capability to provide sufficient grounding to allow the starter to engage (clicking).
You aren’t using the starter when push starting the car.....
I don’t believe the ignition switch would produce the flickering of the fault lights as described.
Idle last thought.... when you jump started the car from another vehicle... was the negative cable clamped to the fender grounding point in the engine compartment or directly to engine. If it was to the frame or grounding point, try again clamping negative cable to engine this time. If it starts, replace engine grounding strap.....
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Clear those codes, push start vehicle, complete a short drive cycle-or until a warning light illuminates,
then perform a new INPA scan. Post back with results, this has gone on for much too long.
Alright everyone, I have done as suggested and through your advice and some trouble shooting on my own and with the Autozone tester I believe it has been narrowed down to the alternator. Here are the reasons why.
Reasons known up to this point:
1) I’ve replaced the battery two weeks ago
2) I replaced the starter a week and a half ago, and the car has turned over up till now.
Newly sorted reasons and troubleshooting:
3) Two days ago, after the problem reoccurred and the car wouldn’t start, I push started the car to get it home, and then next day when I went to try to start it all the settings (clock, mpg, etc) had reset.
4) Today when I got back and the car had been sitting for 18 hours, I tested the voltage to be 12.39V.
5) I did the jumper cable connection from the engine to the chassis to check for poor ground, and it wouldn’t start. I tried multiple mounting points.
6) I brought the Z4 to Autozone (they have a tester that can test alternator, starter and battery on the car). The results of the alternator test program was that the voltage when the car was running was 11.74V (very low), and the result of the battery test was: “BATTERY GOOD, NEEDS CHARGING” according to the tester device.
7) I think this is *the most clear* symptom: on the drive home from Autozone, the yellow warning lights (DSC, Active Steering, tire pressure, etc) all flickered on. After giving it some revs to a higher rpm, they immediately went right back off. I then let the revs drop and they flickered right back on, I did this several times.
I have ordered a replacement alternator which will arrive tomorrow, and intend to swap it out as I’ll be heading on a road trip this weekend (about 2 hours drive) and with a new alternator that should give it a great chance to charge.
What do you all think now that I have done some additional trouble shooting?
Here is the video that I took last night on the way back from testing at Autozone, the lights came on, and then as soon as I increased the revs they disappeared. I let them fall again, and the lights flickered back on, and then revved again and they disappeared.
Probably the alternator. Also, with the battery not being able to recharge since you bought it it might be shot now although Im no battery SME lol
Fingers crossed it's still good, if the battery is shot maybe I can finagle a free replacement, I'm not sure though.
I'll update this after the replacement goes through, it seems pretty straightforward to replace the alternator in these cars, especially with the long bonnet, but I'll find out shortly.
Just an FYI as I dont know if your car fell under the PCV recall but they replaced my alternator bolts in the process of the recall
Last edited by psycleridr; 07-26-2018 at 05:14 PM.
Put the new alternator in last night, and this morning when I came outside I knew I'd have to push start it to give the alternator a chance to charge the battery. Battery measured 12.1V before leaving, too weak for lock/unlock lights to flash. Drove 30 minutes to work, lights flashed when I locked the car. Fingers crossed it starts when I go to start it after work. Will update this after work.
Hey everyone,
Just wanted to provide an update now that it has been about a week since I replaced the alternator and I've done all kinds of mixed driving (short and long trips, periods of no driving and quick restarts, etc). I'm glad to say the little Z4 is doing very well and hasn't let me down as of yet. There was one time where just after replacing the alternator it wouldn't start, but after giving the clutch a good working up and down it started up fine, so maybe I'll have a clutch switch swap out become necessary down the line?
Aside from that, for the past 6 days everything has been absolutely peachy, so it looks like the battery just wasn't being charged enough via the alternator. Battery needed to be changed anyway (it was about 6 years old), and while the starter may have been good it was a good experience and at 120,000 miles I'm not opposed to having a new one. Thanks again for everyone's help!
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