Most frustrating car ever!

[TwoWheelJay]

So i love my bimmer, but lately it has done nothing but piss me off. Its a 92 525i with the m50. I just had the front suspension done (still has small shimmy but that may be an improperly balanced wheel). A couple weeks ago trans program flashed at me a couple times, and i needed to replace the pan seal because it leaked fluid out (and then pissed fluid all over). Now the trans program light comes on once in a while, with no real reason. Randomly my car idles lumpy and wont accelerate unless you go WOT (this goes away after like a minute usually). It randomly had a tailight out (which got me a ticket) and then went away the next day. I have some trouble starting unless i put the key to "on" for a few seconds before i crank. and today the battery just randomly died. like not even enough power to open the locks. WTF. It seems like something must tie in all the electrical issues, i cant imagine that many seperate systems all have something wrong. Is ther any one thing that may affect all of them? dme relay or someshit? HELP i cant go without a car, i work 2 jobs 6 days a week + school.

[joshua43214]

Start with the trunk hinge wiring harness, it will cause intermitant tail lights and its conceivable that the door lock wire could short to the tail lights causing the battery to go dead. A good battery should be able to take having the brake lights on all day though, so maybe you have a crappy battery or and old one.

[TwoWheelJay]

anything else, the random trans prog and other issues are annoying as hell, and i cant keep throwing money at the problems individually.

[BillionPa]

my battery dying caused the trans prog message, then i got an optima and havent seen it since.

when was the last time you replaced your fuel filter?

also you should clean the hell out of the ICV, throttle body, and air flow sensor.

also double check the air filter, and run a few tanks with fuel injector cleaner.

[TwoWheelJay]

my battery is only 5 months old if that... Havent replaced fuel filter, ill try that next. TB and air flow were cleaned last night, air filter is good its only a couple months old. I cant imagine my trans is seriously messed up, since the old owner told me it was rebuilt and i think i can find paperwork in my pile that has a receipt for it. I hate to do it but i think i may have to take her to the stealer for a diag.

[joshua43214]

Not to beat a dead horse about the battery, but just because its 5 months old does not mean its good. Even the best battery makers will sometimes provide a bad battery off the shelf. It would take a pretty big draw to kill a good 5 month old battery. So either you have a large parasitic draw, or you have a junk battery.

There are lots of good places to buy cheaper parts, but the battery should always be top of the line.

[TwoWheelJay]

Lol, i work at NAPA. The battery is a pretty big f*cker and it seemed just fine when i bought it, maybe it was just kinda bad. idk i can warranty it if thats the issue. I dont know where i would have a bad draw, stereo is all hooked up with proper harnesses and such. Do you think any of my other symptoms may reflect a draw? i cant imagine the dme thing would somehow pull a ton of current.

[joshua43214]

Ya, NAPA batteries in my experience are quality. I would have a look at the trunk hinge harness, and pull the head unit to double check that the turn on signal for the amp is on the correct wire. Easy to make silly mistakes and hook up the amp to a keep alive power. Check alternator output too, maybe you are just runing arround on battery power all the time, the alternator can fail and not turn on the battery light.

If you don't turn up any thing obviouse, you will just have to hook up an amp meter and start pulling fuses, not fun in a BMW backseat I know.

As BillionPa stated, low battery voltage can cause trans program lights and other performance issues.

[Ausmpower]

Check the alternator output voltage (You want to see 13.8 - 14.4 volts), the reg can fail supplying too high a voltage and fry the battery (warp the plates).

Check the main earth points to the battery also.

Issue 2. (The wait before cranking):

You either have a suspect fuel pump, fuel pressure regulator or a fuel leak before the injector rail. The reason you have to wait is for the fuel pump to repressurise the fuel system before the engine will start.

Check the small supply hoses that lead into the fuel rail first, they sometimes get old and start to get small slow leaks.

HTH

Ross

[TwoWheelJay]

thanks for all the help guys. I suspect my alternator. I had some doubt about it before, but i guess when i replaced the battery, it was enough to compensate for the alternater at the time, i wil check tonight.