My S reg. 5 Series BMW Touring has an intermittent - could be 2/3 times a week - no start problem.
I switch on the ignition and all the panel lights up as normal. Turn the key to the start position and absolutely nothing happens - no clicks, no whirring noises, no dimming of lights. I sometimes have to turn the key 7/8 times before it will start and then no problem during the running. The symtoms occur with either key.
BMW have interrogated the fault computer and found nothing. Tracer lights attached to the starter suggested that when a no start occured no volts were getting to the starter. Both the ignition switch electrical block and the immobiliser aerial have been changed to no avail.
Has anyone any ideas. BMW say they haven't heared of the problem before - but then they said that about the high sulphur petrol bore liner wear problem too ! !
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Check the starter relay and connections.
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As I mentioned in my original mail, I have had a tell tale light fitted at the starter motor which did not light up when the fault occurred thus leading me to think that the problem was further up the line. However, if there is another relay at the dashboard end then that will be something else to try.
Check the starter relay and connections.
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How about a faulty ignition switch or relay? As someone said on this site recently, you want someone who is a bit more practical than the "hook it up to the computer" type approach. I really find it diificult to believe that this fault is so hard for a experienced man/woman technician to sort out. I do not claim any expertise but the ignition switch itself seema a prime suspect in your investigation. Mikey
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This is a known problem on BMW 5 Series.
I know of 3 friends/colleagues who have all had the same problem and all been told by BMW dealer (2 of them by the same one) that it's not a known fault and they've never had it happen before.
None of them were cured to my knowledge but I shall try and check over next few days and come back to you
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My money would initially be on the starter relay (BMW have had problems with sub-standard relays). If not that then take a look at the immobiliser. Immobiliser status should be easy to check by the dealer, leaving no doubt as to whether its at fault or not.
This type of fault should be dead easy to diagnose for a competent dealer. Complete reliance on ECU fault codes is a weakness of many dealers - there are plenty of faults that don't set a code. I trust they did not charge you for their half-baked attempts at rectifying the problem?
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Are you talking of a relay on the starter itself - in the good old days I used to call these the starter solenoid - or is there another relay at the dashboard end of the line ? I have had some tell tale lights fitted to the starter end which didn't come on when the problem occurred - thus eliminating the starter I thought. However, if there is another one . . . .
As I said originally, the main dealer recons the immobiliser is O.K. I suppose an intermittent fault must be that much more difficult to diagnose.
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Even if your friend's problems have not been solved, I would be interested to know what they have tried as a cure.
I'm sure BMW have a policy of fault denial as with the low sulphur petrol bore wear problem I was asking them about before I bought this car. The internet had reams of data about it but my local agent denied all knowledge of it.>> This is a known problem on BMW 5 Series.
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There is a starter motor relay (in addition to the solenoid - which is a form of relay) located in the electrics box under the bonnet. IIRC on the nearside. The starter relay is relay 'No. 3' adjacent to the engine ECU. When you turn the key and the engine is not starting see if this relay is clicking - it should.
You can test the relay by connecting 12V across its terminals 86 and 85 (+ve to term. 86) - it should click.
As regards what BMW dealers tell you - don't believe a word of it. BMW is all about brand management and 'lifestyle' - they'll tell you any nonsense that comes into their head (I'm using very restrained language..).
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Sorry - electrics box is on offside inner wing on your model, I think. Its the one with the engine management ECU in it.
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There is a starter motor relay (in addition to the solenoid - which is a form of relay) located in the electrics box under the bonnet. IIRC on the nearside. The starter relay is relay 'No. 3' adjacent to the engine ECU. When you turn the key and the engine is not starting see if this relay is clicking - it should. You can test the relay by connecting 12V across its terminals 86 and 85 ( ve to term. 86) - it should click. As regards what BMW dealers tell you - don't believe a word of it. BMW is all about brand management and 'lifestyle' - they'll tell you any nonsense that comes into their head (I'm using very restrained language..).
Thanks. This is the most promising reply to date. Since I don't have a personal E-Mail address for you you'll just have to keep watching this space for an update. This is one of the big problems with an intermittent fault - it could be a week or so before I am able to check your theory.
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I would recommend testing the battery, a dead cell could be the cause of your problem. Not all BMW dealers deny the bore wear problem, the dealer I used to work for did not. We used to work till the early hours changing block and pistons under warranty. As an ex-employee of a BMW dealership I disagree with "they'll tell you any nonsense that comes into their head".
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As an ex-employee of a BMW dealership I disagree with "they'll tell you any nonsense that comes into their head".
As an ex-customer of BMW (and likely to remain so) I stand by my comment. Obviously dealers vary, but the one I used (part of a very large dealer group) must have thought I was found under a gooseberry bush. Worked most of my life in the motor business (working as a technician and graduating on to design work in the motor industry, inc. for BMW in Munich) - so I know when I'm being spun a line.
Classic tale was some years back when they had the header tank pressure cap recall. I was going past the dealers so took the old cap and Reg. Document with me. Dropped in at the dealer and they confirmed the car was due a new pressure cap. Then they told me that 'we have to fit it'. Wouldn't give me the cap but wanted me to book the car in!! I grumbled and they then explained that BMW's were complex cars and only their trained technicians could fit the cap, 'to make sure its done properly'.
I didn't have time to waste with them so walked out and then dropped into ECP and got one for £10.
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Bore wear wouldn't have anything to do with your no start situation. In addition to what aprilia mentioned I would look at the actual ignition keys also. If I remember correctly the key/s have a small transponder type chip in them and it is possible that those have gone bad. I have read on various BMW forums that you should always use your spare key as the chip is "recharged" through the ignition and leaving it in the bottom of a drawer somewhere will do it no good. Any chance of the dealer coding a new key for you, but delaying payment until you know it works?.
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There are two types of key on models of this age (S reg). One type has replaceable batteries and the other has rechargable batteries. To recharge the batteries you only have to use the key once a year for about an hour or so.
You can reprogramme the keys yourself (although a dealer might not tell you so...).
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