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kppeters 01-15-2013 02:11 PM

engine/alternator trouble
When my car is idling it drops to nearly stalling unless i rev the engine. Sometimes the engine will stall if I do not catch it in time. On 1/3 of those occasions when the car does stall, it will not restart for anywhere from 1 - 5 minutes. At other times the car runs just fine with no trouble. This trouble does not occur every time I drive the car and does not occur just when the car is cold. It can happen anytime and regardless of the engine temperature. I had the alternator go out two or three years ago. I had it rebuilt for a fraction of the cost of a new one and installed it with no trouble. The car was fine after that until about eight months ago when I finished up an errand, got into the car, drove to a stop sign, and it died. It would not start for nearly fifteen minutes. I went through the summer with no revving trouble, but occasionally the car would just not start. I finally went ahead and bought a new alternator and installed it. The car was fine for a time and then the trouble started with the RPMs dipping so low and the times it would just die. Once it died as I was slowing down to make a turn. I felt my steering wheel tighten up, looked down at my dash, and realized it had died. It started up right away then. My car is a manual transmission and I have owned it for 8 1/2 years. I love the car but I find myself feeling lucky every time it starts and I get home and back safely. I have three children so I do not want to get stranded. About four weeks ago, I started up the car one morning and the engine sounded horrible. Really rough and ragged. After that initial time, the rough sound went away for a week or two. Then it came back and now every time I turn on the engine it sounds bad and I can often hear an odd almost clicking sound (if I am standing outside the car) when the engine is idling. These are just a few of my problems. Any help that you all could give me would be great. I have other issues with the car but I can go into those at a different time. :)

pleiades 01-15-2013 02:23 PM

Do you have a check-engine light on, or any other lights like the red battery light glowing?

If the alternator were your problem, it wouldn't charge the battery well if at all and you'd eventually have a dead or weak battery. Also, if the alt weren't charging, that battery light on the dash would be on. I'm not saying it's not the alt. The refurbished or replacement alt could be going bad, just that it sounds like your problem is something else. Maybe a failing MAF....

You should go ahead and describe your other problems. If you have a code scanner or know of a local automotive shop (like Autozone) that'll read the codes for free, you should see if the car is giving any codes. Those would tell the forum folks here a lot more about the problems your car might be experiencing.

JKRIT 01-15-2013 03:27 PM

Vanos seals; DISA valve; Idle Control Valve (ICV) are some possibilities, and maybe a trifecta of all three at once. DISA is very easy to inspect, but ICV is more likely to make clicking noises.

kppeters 01-15-2013 04:25 PM

My battery light went on the two or three years ago when I initially rebuilt the alternator. I had no ability to reset the battery light so it has been on ever since. I do not think the battery is bad or the car would not start, right? I have no check engine lights on except the red battery light, but again that light has been on since my initial alternator trouble.

As far as my other problems, I think my car has electrical trouble and has had it for a while. The traction control system went out also about six months ago. I got an estimate to have it replaced and it would almost cost more than the value of the car. When I have the defrost running I can hear this annoying chirping sound. I finally broke down a year ago and fixed the back hatch. It got jammed or stuck or something and for a year I lived with only being able to open the glass portion of the rear hatch. I finally decided to spend the money and get it fixed.

I love this car. It is a great trip car, spacious and roomy and smooth. It is easy to drive (well not so much right now). I do not want to put a small fortune into it because of its age and value but I would love to drive it for a few more years. My husband wants me to get a minivan but I cannot get a minivan in a manual transmission and I love driving this car.

I can take it to an autozone tomorrow and see if they can read the codes.

pleiades 01-15-2013 05:28 PM

Autozone should be able to read the generic fault codes (for free), which might be enough. BMW-specific codes will require a trip to the dealer or a BMW specialist shop.

Difficulty starting the car could be due to a failing sensor (among many things). Mass air-flow sensor (MAF), cam position sensor (CPS), crankshaft position sensor (CKP). It could be a bad ignition coil. If it's a failing MAF, sometimes the car will run great if you unplug that sensor. (That's basically the diagnostic test right there.)

The traction control system could be out simply because of a failing wheel sensor, but no doubt the repair shops will want to replace everything and laugh all the way to the bank. Someone else will have to tell you how to diagnose this.

You might want to start separate threads for each of the problems your car has now.

The battery light should go out on its own I think (not 100% certain), unless the charging system is still faulty. This topic could get somewhat involved. I understand from your first post that the car now has an entirely new alternator. Did you obtain the new unit from the dealer and install exactly the same brand (Bosch or Valeo) and amp rating (should be 120A I think)?

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