Engine Problem...need help? w/ vid

[WERKSHOPe30]

date 6/17: while driving 75 mph up the I5 (San Diego), it was fine one second then the next second the car began shaking violently and making crazy knocking noises...i pulled over on the freeway and let the car run.  The motor sat there on idle, and i noticed the idle was really rough...i tried stepping ont he gas to make sure it wouldn't stall but it bogged down, then it stalled....i started the car again, and with no problem it started up again...the idle was still rough and the car still had a shake (like a muscle car shake while it idled) the whole car was shaking))...i opened the hood and heard a knocking noise coming from the engine and seemed like a knocking coming from under the car. At this point i got back in the car and rev'd up the motor to see if the car would lose the vibrations after a certain RPM (since i had shakes prior to when i changed my O2 sensor a week before).  The noises just got louder when i rev'd the motor.  Since i was only 50 feet from the next exit i opt to drive it just to get it off the freeway, while doing so i couldn't get the car past 45 mph (as if i really should have tried to drive it anyways).  The car had a dramatic lose of power, through all the gears...i even struggled to get up the exit.  Pulled into a gas station and called a tow truck. On a lighter side the car still looks good...

date 6/18: tried some spark plug test to see if removing the SP wires while car was on would kill the car...well, cylinders 1 and 3, so i changed all 4 of the spark plugs...those two SP were black on the tips, changing all four SP didn't change anything to help the problem at least noticeably...My buddy had lent me a compression gauge, so earlier today i checked my compression and every cylinder gave a reading of 190.

date 6/19: Checked for spark, cylinders 1,2, and 4 have spark, but 3 does not.  My buddy had mentioned changing the coil packs.  but im not mechanically inclined to do more than the basics of working on my car.

if anyone can help me out on this problem, i would really appreciate it. thanks

**here is a video of how my motor is sounding like...

[WERKSHOPe30]

237,456 miles on my car by the way...without a rebuild.

[D. Clay]

Take the spark plug cover off the valve cover and follow #3 plug wire to #3 coil on right front fender apron. Check the plug wire with an OHM meter. Specs are in the repair manual. If it's OK you probably need a coil. They're easy to replace and cost $49.90 from BMAParts.com. Buy something else (you should go ahead and replace all 4 of them or go to a COP conversion) and shipping is free if the order is over $50. A dead cylinder on a four banger is a lot more noticeable than on a 6 or 8 cylinder motor.
http://www.m42club.com/forums/showthread.php?t=1682&highlight=returned

[Massimo]

I had idle probs with my old e21 318i. It had an eratic idle and shaked like a
v8. I worked out that there was a vacume hose or oil cap that was loose. Maybe have a look under the car see. hope that helps

[WERKSHOPe30]

these are all great suggestions which for the most part i have already tried and after chaning the coil pack it still has the problem...Massimo i will definitely try that approach next...i was hoping to figure this out before i decided to take it to my e30 mechanic, but at this point i might just need to get over it and bring her in...

thanks for all the help. much appreciation.

[neo1985]

mine has exact same problem.. and mine just looked like yours

[B318M42W]

coil feed from the ECU gone bad? ground strap not grounding anymore?