Help! Car won't start & it's not battery (I think)

[metzger]

Guys:

Was going to put a new battery in this afternoon just for preventive purposes (car is 02 and had heard they only are good for around 4 years). Car will not start. Current battery "eye" shows green (according to manual this means it's charge and OK) - it has been on a BMW battery tender since I bought the car.

When I turn the key all interior lights come on and I can hear a click that may be the starter solenoid, but starter doesn't turn over. Also, right front headlight flashes once.

Thought it might be something to do with car's security system, so used key to lock/unlock doors (no change).

Thought maybe somehow the key had been deactivated, triggering vehicle immobilizer, so tried other key (no change). As it's 3 on Friday and my dealer is 60 miles away, any ideas on what the problem could be? Thanks for your help.

MikeMike Metzger
2002 Z8 (silver/black)
2006 650 sport coupe (silver gray/chateau)

[tomfakes]

This is the battery. I had this for the last month or so. Got a new battery yesterday. Jump starting worked for me, after the donor car had run for a few minutes to charge the Z8 battery a little.

The headlight thing sounds strange.

Try the jump start before you call the tow truck.

[Z8Eldred a.k.a. The Mudman]

a five year old battery and it works fine. I had the original battery replaced by the dealer three months after I bought the car becuase it was discharged by the phone wiring harness. When the harness was replaced the battery was replaced as well.

Although mine is five years old I have had no problems with it. It has never been discharged and I always use the battery tender when it sits for longer than a week.

[Z8mania]

If you try to jump it from the jump terminal in the engine it will not work. You need to jump the car at the actual battery. However, your battery is so far gone that it will not recharge when you drive it. So if you need to go somewhere, like to the dealer for a new battery, be prepared to either have them install it right there or get jumped again. I just drove to the dealer and had them put it right in.

The batteries last about 4-5 years. Preventative maintenance I think everyone should do is replace the battery every 5 years and also every 3 years have the MAFS checked (mass air flow sensor (there are two)). There is no way for you to know how the MAFS are doing unless you have diagnostic tools- the easiest thing is to report to the dealer that the car feels down on power and you think its the MAFS- they get dirty a little too easily in my opinion. If you are under maintenance then they should be replaced free of charge to you. If not each one will cost aprox $350. Pricey- but when I got mine switched out it felt like a new car. They are critical to the performance of the engine.

So if you are going to the dealer for a battery, you might as well have the MAFS checked too.

Hope that helps. Happy motoring!

[metzger]

Took my other car and went to buy a new Interstate battery. Installed it and the car started right up. Original battery still showing green eye, but obviously didn't have the juice left to turnover the car. Thanks for all your help!

MikeMike Metzger
2002 Z8 (silver/black)
2006 650 sport coupe (silver gray/chateau)

[tlc]

[tlc]

Mike,

Sorry to tell you this but I don't think that your problem is solved long term. I have had the same problem intermittently for at least a year. It has been in the shop twice before without a permanent fix. It is not the battery. Lights or nothing else works when you have a dead battery. I have left my Alpina at the dealership for the last 3 weeks. They occasionally experience the problem of no start and are able to get data that they say will help them find the solution. Pin 40 seems to be the area of focus currently. I hope that your problem does not repeat, but if it does, post and I will hopefully be able to give you the BMW solution to your problem.

Terry

[m6doc]

old too (9/02 build date) and having battery issues. Goes completely dead without driving it for more than 3 days. Never has had this problem until recently. Dealer checked battery and says "nothing wrong" , even though the "eye" is black at all times (even when the trickle charger light says it is charged completely !!

Interesting thing here -- I have a battery tester. On my 1988 M6, the BMW battery is about 3 years old, and when testing it as a reference, the "eye is green" and it reads on the tester 13.2 volts with 135% capacity at rest (after discharging the surface charge).

On the Z8, the eye is black (never green anymore), and tests 13.2 volts with onl 97% capacity. The charging system checks out so no defects there (again, surface charge discharged before testing).

The battery tester info states that any battery lower than 80% is marginal and less than 60% needs replaced on a maximum 100% scale. Interesting that the M6 reads in excess of the 100% mark. If adjusted ( I have no idea whether I can convert this to the other scale) but that puts my battery at or below the replacement level capacity %. My car is still under warranty, but my dealer seems reluctant or incapable of diagnosing the issue -- so, I will most likely follow your lead and buy a replacement.

Any thoughts on a brand or should I stay with another OEM? I have heard Optima has an equivalent that is about half the weight and is smaller and makes more room for additional storage??

[Z8Eldred a.k.a. The Mudman]

battery is now starting with a slight delay, although I have kept it on a trickle charger for the better part of its life when the car is not driven for in excess of four days.

I will replace it with a douglas type battery this weekend and have the MAFS checked when I take the Z8 in on Nov 6th for the Performance package upgrade and the new 3.64 LSD.

Thanks Jerry.

[Z8Eldred a.k.a. The Mudman]