So, i'm finally home from college. naturally, the first thing i wanna do is take the 6er out for a spin. starts right up, and boy does she like to go fast. it's a rainy day, halfway home it starts to pour. i come to a stop sign and she starts to idle extremely rough. bouncing off 500 rpms and chugging roughly. more intensely than just a rough idle. i give it some gas, get home. pull into my drive and put her into park and she hops up to 900rpms and idles steadily. back into drive and shes struggling again. I turn the car off, and when i go to turn it back on, she wont start.

While i was driving, occasionally, i would go to accelerate and around 2300 rpms the tranny would start to "chugg" up to 3000, drop back down to 2300 and the process would repeat. didnt do it every time, and it definitely wasnt slipping.

I went out with some friends, and just took her for a spin. she started right up, and the transmission didnt do anything weird, except for just once. she just came back from the mechanic who said she looked solid except for a bad suspension pump. He's been nothing but trustworthy and he's got a soft spot for old bmw's, and owns a sixer himself so im sure he would have noticed if something seemed really off.

Does it sound like the wiring just needs to be replaced, or does the transmission issue seem like something more serious?

_{as you can tell i know jack shit about mechanics}

Bad Idle? Not sure on the six series, but the first thing I'd check on my M3 would be the ICV. (Idle control valve)

Posted by Sinister Crayon Bad Idle? Not sure on the six series, but the first thing I'd check on my M3 would be the ICV. (Idle control valve)

ooops, i should have mentioned that when its dry it idles perfectly fine.

rain + what you described sounds like old/bad spark plug wires.
do these Beemers have distributors or are they DIS? If it has a distributor, i'd say cap, rotor, plugs and wires are in order.

i know with a GM, the DIS coil boxes, when they get some age on them, crack around the bolt holes and do all sorts of funky shit when it rains or is extremely humid.

i would start with plug wires, maybe spark plugs while you had your hands in it.

one of my friends used to diagnose plug wires by taking a spray bottle of water and mist it over the wires while he held the throttle open... you could actually see the arcing when the wires were bad.

i've never tried it myself...

Posted by Samurai rain + what you described sounds like old/bad spark plug wires. i would start with plug wires, maybe spark plugs while you had your hands in it. one of my friends used to diagnose plug wires by taking a spray bottle of water and mist it over the wires while he held the throttle open... you could actually see the arcing when the wires were bad. i've never tried it myself...

I did that just yesterday with the spray bottle to prove to a customer that the wires in their Sebring were fukt. You will hear a popping noise.. and if you're paying attention closely you will see the arc.

Definitely agree. wet weather, poor idling...start with plugs & wires

Posted by oddspot I did that just yesterday with the spray bottle to prove to a customer that the wires in their Sebring were fukt. You will hear a popping noise.. and if you're paying attention closely you will see the arc. Definitely agree. wet weather, poor idling...start with plugs & wires

as if driving a Sebring wasn't fukt enough!

Posted by Samurai as if driving a Sebring wasn't fukt enough!

It was worth every second of my time just to look at her! Smokin Hot!!! (the girl who owned it, not the car)

Posted by oddspot It was worth every second of my time just to look at her! Smokin Hot!!! (the girl who owned it, not the car)

lulz.

is it possible that the wireing has to do with the transmission acting up also?

is it automatic? maybe

rough idle plus misfire sounds like your wires are cracked and moisture is getting in

yeah, its an auto